Gerard W. M. Visser and
Albert D. Windhorst*
Amsterdam UMC, Vrije Universiteit Amsterdam, Dept. Radiology & Nuclear Medicine, De Boelelaan 1117, 1081HV Amsterdam, The Netherlands. E-mail: ad.windhorst@amsterdamumc.nl
First published on 19th August 2021
The alliance between the reigning quantum mechanical atom model and chemistry still is a difficult one when it comes to an adequate explanation for e.g. the covalent bond, inversion, chirality, or hydrogen bonds. Overruling Rutherford's extrapolation from gold to hydrogen, an atom model is described that provides improved answers to these phenomena while the hybridization principle and the covalent bond are re-defined by giving neutrons a much more prominent role than they have in the reigning quantum mechanical model. It is postulated that a neutron is not just there to assist the strong force in surpassing the repulsive coulombic forces between the protons in the nucleus, but the neutron is the modus operandi of molecular geometry, and as such plays a part in chemical reactivity, bond length and bond strength.
With respect to chemical aspects, the octet rule (1916) had been implemented as the closed shell principle, the “Aufbau principle” had seen the light, and Pauling7 had developed the hybridization concept (sp3 for single-bonded carbon, sp2 for double-bonded carbon, sp1 for triple-bonded carbon) as a proposition to account for the otherwise inexplicable fact that e.g. CH4 contains four equal CH-bonds. This hybridization concept also solved the issue of how a p-electron crosses a node and passes through the positively charged nucleus. A covalent bond became the result of overlap between two orbitals (two interfering waves, each with one electron) and two paired electrons, inversion (e.g. the NH3 molecule) and hydrogen bonds became the result of spontaneous tunneling.8,9 Even empty orbitals could exhibit chemical reactivity such as the empty p-orbital of boron and alumina, and empty d-orbitals in case of octet rule disobeying compounds like H3PO4, H2SO4 or HClO4. The octet rule disobeying HNO3 remained a nuisance, because nitrogen's quantum number n = 2 forbids the presence of d-orbitals; only a Lewis structure remained descriptive for this compound.10
At around the time Ogilvie questioned the whole orbital concept,11 we added an extra dimension to Pauling's geometric s-electron hybridization parameter. Organic fluorine chemistry is rather unusual and numerous dichotomies exist.12 Some of these are accounted for by hypotheses like ‘double-bond no-bond resonance’13 or ‘large repulsion integrals in the carbon-fluorine region’.14 In an attempt to improve on this, we launched the concept of the s-orbital density deficiency of the F-atom as the driving force of its chemical behavior.15–17 This concept was based on the quantum mechanical fact that lone pairs require more than their s-share in the sp3-hybridization process.18 Since F possesses three lone pairs, we postulated (1) that the F-atom is urgently in need for additional s-orbital density via its bonding orbital, to release this tension (see Fig. 1), and (2) that the hydrogen atom and the carbon atom are the perfect s-orbital density donors for the F-atom.
According to this concept, the F-atom in F2 is the most s-orbital density deficient, leading to a weak F–F bond and extreme reactivity; in CH3COOF this situation is slightly better and therefore it reacts less vigorous. Over and above that, although being the most electronegative element in the periodic system, when present as fluoride in water, the F-atom immediately shares its extra electron to form HF in exchange for s-orbital density, whereas fluoride is a strong nucleophile in the absence of H2O. The concept also made clear why in organic chemistry the F-atom prefers to be bound to sp3-carbon over sp2-carbon: the sp2-carbon atom had to use a great deal of its s-orbital density to construct the double bond and, therefore, its s-orbital density donor ability towards fluorine is diminished.
Later on, we reported that in a series of mono-substituted benzyl analogues of thioperamide, the aromatic F-derivatives showed, in contrast to computer predictions, a factor 10 less in vitro activity than its H, Cl, Br, and I counterparts (Fig. 2).19
We postulated that the aromatic ring of the fluor derivative was not flat anymore,20 because F had forced the sp2-carbon of the aromatic ring to re-hybridize into a sp3-like carbon, leading to a Dewar benzene-like structure with reduced affinity for the receptor. In addition, we argued that also for fluorobenzene itself the literature data21 (ipso angle increase and apparent bond shortening plus angle decrease for C2 and C3) strongly point to a non-flat configuration (Fig. 3 and 4).
Fig. 4 Apparent bond shortening and angle changes when projected in flat fluorobenzene (angles and bond lengths are from 21). |
The last decennia we have tried to find an adequate explanation for the re-hybridization phenomenon. We gradually came to the inevitable conclusion that the reigning atom model needed adjustment, and hereto some serious ‘out of the box thinking’ was required. Besides finding a concrete answer to the fluorine problem, it would be an added bonus when at the same time this renewed atom model would also comprise an adequate solution for phenomena like inversion, chirality and hydrogen bonds, and the reason for stability and instability of an atom. In this paper we report our proposal for such an atom model adjustment. The renewed atom model is based on the key premise that Rutherford's extrapolation of the findings for the heavy gold atom (Z = 79) to the lighter atoms, is not correct.
The new model will be discussed along the following lines:
(2) This flexible constellation of neutrons and protons is strictly organized. Two protons are always separated from each other by a neutron; two neutrons are always separated from each other by a proton.
(3) In each constellation a neutron can bind to three protons at most, a proton can bind to three neutrons at most, because each have three strong force related quarks.
(4) In the strictly organized constellation of neutrons and protons each electron remains revolving in a probability cloud around its proton.
(5) A “square” proton or “square” neutron can be part of the strictly organized constellation of neutrons and protons. A square proton is defined as a proton that carries an electron that is too low in energy to chemically bind to another atom and therefore needs to become activated by a neutron (hybridization); a square neutron is defined as a neutron that is too low in energy to activate a square proton or to take part in hybridization.
Nomenclature used for the subunits at the basic building block:
(a) PN is a proton at the anchor neutron side of the basic building block; NP is a neutron at the anchor proton side;
(b) DN is a subunit consisting of a neutron and a proton at the anchor neutron side; DP is the same subunit at the anchor proton side;
(c) TP is a subunit consisting of two neutrons and a proton at the anchor proton side; a TN subunit is only present in extremely short-living radioisotopes.
(d) and are subunits consisting of two protons and one, two or three neutrons, respectively, at the anchor (N or P) sides, and correspond chemically with a lone pair and quantum mechanically with a filled subshell; and are only present in extremely short-living radioisotopes.
(e) The * in subunits and indicate that they bear a square neutron; PN and nearly always bear a square proton.
(f) A covalent bond implies formation of a “chemical” helium-unit between a PN, DN, DP or TP subunit of one atom and one of the subunits of the other atom.
(g) In the figures, the neutrons are depicted yellow, the protons blue; square neutrons are depicted as yellow stars, square protons as blue stars; in unstable atoms, neutrons are depicted pink, protons red. For the sake of clarity, in atoms Z = 5 and higher, the anchor neutrons of the basic building are depicted white, the anchor protons dark grey.
– A nuclear reaction is denoted as X (a, b) Y wherein X is the target element, a is the incoming particle, b is the outgoing particle and Y the newborn isotope; as a consequence of the impact, radioisotopes produced in a cyclotron or neutron generator do not contain square protons or square neutrons.
– Because in the new model every proton is separated by a neutron and visa versa (thesis 2, vide supra), the newborn proton formed after β−-decay requires a shift within the constellation of the atom (away from the proton to which the disintegrated neutron was attached). The newborn neutron formed after β+-decay needs a likewise transfer (away from the neutron to which the disintegrated proton was attached).
– An isomeric transition (IT) is a transfer of a neutron within the constellation of the atom to an energetically more favorable position (often temporarily better).
– Electron capture (EC) implies a transfer of the newborn neutron away from the neutron to which the proton was attached before capturing its electron.
Most of the production routes and decay modes can be found in the book Radionuclide Transformations.22 Because individual referring to physicists involved in accurate determination of half-lives and isotope abundancies would make the reference list extremely long, we would like to thank them warmly here.
The block contains as subunits at the anchor neutron side a and a DN, at the anchor proton side a DP and a TP. The anchor can flip, leading to chemical inversion in so-called SN2 reactions. The atom exhibits stereo isomerism in case four different chemical groups are bound to the atom: the inverted constellation is the enantiomer of the non-inverted one (Fig. 6).
Multiple bonds formed in the new model are intrinsically the concretization of the banana or bent bonds, whose description had already been shown to be energetically superior to the symmetry-restricted σ, π bond representation of Hückel.24–27
The subunits (PN, DN, TP, DP) can form several double and triple bonds combinations, dependent on the history of the sample and the chemical group R. One may, however, expect the most energetically balanced, symmetrical molecule to be formed, especially at higher temperatures. In that case, the favorite combinations in double bonds, therefore, will be (1) DP with TP, and TP with DP, (2) with TP, and TP with or (3) DP with DN, and DN with DP. Option (1) will be the case in e.g. ethylene (C2H4) with the hydrogen atoms at the hybridized . Allenes provide an elegant example of option (2) and (3) in this respect, because in allenes the central carbon atom possesses both favorite symmetrical combinations, giving rise to the well-known two-bladed propeller geometry.28
The favorite combination in triple bonds will be DP with TP, TP with DP, and DN with DN wherein the neutron of TP is hybridized with . In e.g. acetylene (C2H2) this bears the hydrogen atom. Molecule N2 also possesses this triple bond combination (vide infra, paragraph 2.4).
The structure of benzene is an intriguing one in the new model. As shown in Fig. 7A, when a symmetrical double bond is created between A and C of two ‘normal’ carbon atoms, B and D end up in a cis-position. So formation of the symmetrical double bond with TP and TP with , leads to a cis-position of the DP's (and cis-position for the DN's). The same symmetrical double bond, but with one of the carbon atoms inverted, leads to a trans-position of the DP's. By combining alternatingly three “normal” and three “inverted” carbon atoms in the way shown in Fig. 7B, for benzene a fascinating structure is obtained wherein a double bond between and TP can be formed to the left and to the right. Or in other words, a resonance system is created that answers the famous Kekulé benzene-structure problem from 1865.29,30 Other examples of resonance, namely between C and O, will be dealt with in paragraph 2.4.
The well-known long-living carbon isotope (t1/2 of 5730 y, decays to ) bears two DN's and two TP's. In the atom there is no obvious place for the additional neutron: an exotic TN is formed, and this isotope decays immediately (t1/2 2.5 s, decays to ). Radioisotope (t1/2 20.4 min, decays to ) bears, compared to , a DP instead of a TP, while in radioisotope (t1/2 19.3 s, decays to ) also the neutron at the DN is missing (Fig. 8). From the latter constellation, it can be concluded that is the last carbon isotope that can chemically react as carbon. For the radioisotopes and there is no obvious place for the proton, and these radioisotopes are therefore extremely fast deteriorating nuclei, ending up as α-particles, mostly via proton loss.
In the new atom model, the weak nuclear force is transformed into a stability rule for each anchor side. The carbon isotopes and allow the deriving of these stability rules. The summarized subunits at the anchor proton side of the carbon isotopes and give n = 3, p = 2, with n for neutron and p for proton. When n = 2, p = 2 or n = 4, p = 2 , the atom is instable. So our new model indicates that in order to be stable, the summarized number of neutrons at the anchor proton side should exceed that of protons by exactly one i.e. should follow the stability rule n = p + 1. Applying the same approach for the anchor neutron side, and counting a square neutron or proton for ½, the stability rule for and appears to be n = p − ½, namely n = 1, p = 1½ for and n = 1½, p = 2 for . Because radioisotopes produced in a cyclotron or neutron generator do not contain square protons or square neutrons (vide supra 1.1), the four carbon radioisotopes and deviate from the anchor neutron stability rule as well. In the new atom model, conversion will, therefore, take place until the new-born constellations comply to both rules.
At the same time, the -atom can be taken as the prototype of an atom that bears a square proton (Fig. 9). Because of this square proton, the is stable and in fact it is the only stable atom in the periodic system with more protons than neutrons. Its abundancy is only 1.34 × 10−4%, so most probably originating solely from the decay of cosmic-produced . With the noble gas , a unit consisting of two neutrons and two protons alternatingly linked with each other, the first row ends. When adding an additional neutron at the anchor proton side, forming , the neutron is immediately emitted (t1/2 0.7 × 10−21 s).
Introduction of a neutron at each anchor proton is too much: when the anchor proton side of is hit by a neutron the composite atom breaks down into and an α-particle ,31 whereas with the (n, γ) reaction on , giving , a radioisotope with a t1/2 of 0.8 s is produced.32
Concerning the stability rules, and both follow the new rules, with n = 1, p = 0 at the anchor proton side, and n = 0, p = ½ and n = ½, p = 1 at the anchor neutron side, respectively. possesses with n = 2, p = 0 at the anchor proton side a neutron too much. Notably, for and neither β−-decay nor β+-decay leads to a stable situation, leaving emission of the additional neutron and proton, respectively, as the only option.
The beryllium (Be) isotopes reveal that the requirements for the addition of the second proton onto the backbone are also very stringent and delicate (Fig. 12). At the anchor proton side, only a constellation wherein the shared neutron is replaced by a shared TP appears acceptable, whereas at the anchor neutron side only a shared is accepted, yielding the atom (100% abundancy).
The proposed deviates from the Aufbau principle, but is perfectly in accordance with the chemistry of Be: linear molecular geometry i.e. formation of linear compounds. In addition, follows with its n = 2, p = 1 at the anchor proton side, and its n = ½, p = 1 at the anchor neutron side the stability rules.
Whereas for lithium the constellation with a shared at the anchor neutron side is already a minority, such constellation for beryllium, i.e. , does not exist. Radioisotope (t1/2 of 0.8 s)33 converts its DN-neutron into a proton at one of the NP's, producing an extremely unstable (t1/2 6.7 × 10−17 s) sort of “open” , an atom that, instead of recombining into a constellation with a shared and shared TP, energetically prefers to break down into two α-particles (Fig. 11). A similar sort of break down was observed for the composite atom produced by neutron bombardment of (Fig. 10). Radioisotope is not the only radioisotope that ends up as α-particles in this way: the boron radioisotopes , after β+-decay, and , after proton emission, also end up as α-particles via this “open” (vide infra). Radioisotope is an unstable Be-isotope with a shared DP between the anchor protons. It can be produced via a (p, γ) reaction on 34 and via a (p, n)35 or (d, 2n)36 reaction on (Fig. 10 and 11). The impact of the proton takes place at the shared neutron between the anchor protons. In the case of the (p, n) on , the neutron at the is thrown out; in the (d, 2n) reaction, the second neutron is the neutron from the deuterium particle that is turned aside without interaction with the nucleus. With a t1/2 of 53.6 d, the proton of the shared DP at the anchor proton side of is converted into a square neutron at the shared PN, giving .
In radioisotope , produced by a (n, γ) reaction on ,37 the shared TP -proton bears a neutron. The atom is unstable, decaying to (vide infra), but it is a very slow conversion (t1/2 1.39 × 106 y), most likely owing to the balance and symmetry in the constellation. For radioisotope , there is no obvious place for the additional neutron: an exotic TN is formed, yielding a very unstable isotope (t1/2 13.7 s), decaying to (vide infra).
The discovery of the neutron in 1932 by Chadwick came from α-bombardment of , producing .38 As illustration of our model, nuclear bombardment with α′s or nuclear transformations in which an α-particle is eliminated from the atom, provide in general too many possibilities to be used as proof by logical argument. But because the α-impact on the atom from four sides is the same, in this special case we refer to Chadwick's groundbreaking experiment. Upon α-bombardment of , the impact of the two α-protons takes place at the anchor neutron and at the neutron at the anchor proton side (Fig. 12). The shared DN and TP subunits at the anchor neutron and anchor proton side break open at the side of the impact. One deuteron-fragment from the α-particle binds at the freed NP-neutron at the anchor proton side, the proton of the second deuteron part from the α-particle is incorporated at the freed anchor neutron while the remaining neutron of the second deuteron part of the α-particle is turned aside without interaction with the nucleus.
Fig. 13 Constellation of stable (1s22s22p) and of radioactive and in the new model, including conversions and some illustrative production routes. |
Fig. 14 Constellation of stable (1s22s22p) and of radioactive in the new model, including conversions and two illustrative production routes. |
Upon bombardment of with protons, a (p, n) reaction gives the short living (t1/2 19.5 s).39 This converts back to via β+-decay, which means that the atom is formed as daughter isotope from as well as from In case of the neutron of the shared TP at the anchor proton side converts into a square proton at the anchor neutron side, while during this process the shared TP and shared DN break open (Fig. 13). In case of one of the DP protons converts into a neutron (β+-decay) and forms a DN with one of the PN's.
Upon bombardment of with protons, a (p, n) reaction gives radioisotope (Fig. 14).40 This carbon radioisotope converts back to via β+-decay. Radioisotopes and are very instable isotopes: (β+-decay) and (proton emission) end up via as α-particles, while decays to with a t1/2 of 0.02 s. The short half-life of radioisotope that is produced by a (d, p) reaction on 41 confirms that two full DN's at the anchor neutron side together with the fact that the anchor proton side bears three neutrons versus one proton, give rise to severe instability.
Both stable boron isotopes and fit with the stability rules, with their n = 2, p = 1 at the anchor proton side, and its n = 1, p = 1½ and its n = 1½, p = 2 at the anchor neutron side, respectively.
Fig. 15 Constellation of the main isotopes of nitrogen (1s22s22p3) in the new model, including conversions. |
Radioactive is produced in a cyclotron in various ways (Fig. 16). It is therefore an effectual isotope to demonstrate the consistency of the adjusted atom model in the field of isotope production.
Fig. 16 Illustration of the consistency in production routes in the new model illustrated by production of (red arrows indicate the point of impact). |
The atom is produced via a (α, n) on 45–47 a (d, n) or (p, γ) on 41b,48–50 a (p, n) on 51 a (p, d) on 52 and a (p, α) on 51 (Fig. 16). In all cases, the impact takes place at the DN-unit (for the impact takes place at the DN-unit and the NP-unit in the way described for the α-bombardment of producing ). The DN is converted into a containing a full energy proton (not a square one), which leads to a fast decay (n = 1, p = 3 at the anchor neutron side). After proton impact on and the rule “last in, first out” is followed: for the square neutron of the is thrown out, for the D*-fragment from the while for the thrown-out α-particle consists of the deuteron-parts from the and (see next paragraph for the configuration of ). In the case of as target material, the combined (d, n) and (p, γ) bombardment,48,49 both producing the same indicate that the proton of the incoming deuteron is built in and its neutron is turned aside without interaction with the nucleus. Notably, for and an additional consequence of the impact at DN is the activation of into a full energy proton.
The atom, either produced in a neutron generator or in the cosmos, comes from a (n, p) reaction on (Fig. 15).53 The neutron is incorporated onto the DP of the while throwing out the square proton of the whereas decays back to by converting the neutron of the newborn TP into a square proton at the DN, forming the
Lastly, atom is, in addition to a (p, n) reaction on also produced via a (p, α) reaction on 54 This (p, α) on giving implies the impact of the proton at the TP of the atom. The thrown-out α-particle consists of the deuteron parts from the and the TP-unit. Thereby these two carbon isotope productions also follow the rule “last in, first out”.
The full-energy proton of the forms the fourth NH-bond (Fig. 17A), whereas the square proton has turned over its electron to this latter hydrogen atom. Notably, the oxygen atom (see next paragraph) can even force both protons of the into covalent bond formation, demonstrating the versatility of the
In combination with carbon, the intriguing existence of Z and E (formerly called syn and anti) isomers for N-alkyl substituted imines (R1R2CNR3) provides a telling example.57–59 The stereo-isomerism originates from the fact that the double bond between carbon and nitrogen is a symmetrical one (carbon–DP with nitrogen–DN, carbon–DN with nitrogen–DP), but with either a “normal” or an “inverted” nitrogen atom (Fig. 6 and 7A).
Fig. 18 Constellation of the main isotopes of oxygen (1s2 2s2 2p4) in the new model, including production and conversion of the instable ones. |
The main oxygen isotope bears at the anchor neutron side the same DN and the same versatile as described above for so n = 2, p = 2½. It differs, however, from by bearing a at the anchor proton side instead of a DP. This lone pair possesses an intriguing property, it is slightly neutron-deficient and is not closed yet (“open” lone pair). The is chemically closed upon interaction with an additional neutron, but not necessarily a neutron from its own constellation. The water molecule forms a beautiful illustration of this latter aspect (vide infra). Notably, one of the protons of this is thrown out in the (n, p) reaction on producing (see Fig. 18).
With regard to other nuclear aspects, and bear with n = 4, p = 3 at the anchor proton side exactly one neutron more than the number of protons, obeying the stability rule. Atom possesses the same anchor neutron subunits as Atom is as neutron-saturated as and are. The latter radioisotopes slowly convert a neutron into a proton, yielding and respectively. In case of the isotope, however, conversion of a neutron into a proton yielding does not occur. In fact, it is the other way around: radioactive decays to In its tenth neutron appears to remain as a square neutron in the pair, as With that, is the first example of an isotope that is stable, despite its n = 4½, p = 3 at the anchor proton side i.e. the first isotope that follows a special anchor proton side stability rule, namely n = p + 1½.
For the atom, produced either by a (n, γ) or (d, p) reaction on ,60,61 or a (n, p) on 62 there is, like no obvious place for the additional neutron, so again an exotic TN is formed. This isotope quickly decays (t1/2 26.5 s) to via conversion of the neutron of the into a proton onto this TN. Isotope is produced via a (p, n) reaction on enriched 63 The proton impact takes place at the TP while the square neutron of the is thrown out (so again last in, first out). Its short half live (t1/2 122.2 s, converts back to via β+-decay) demonstrates that a n = 3, p = 3 at the anchor proton side is an unacceptable situation. Atom (t1/2 70.6 s) is the last atom configuration that may chemically act like oxygen and decays to Atoms and are extremely unstable, these decay to or and or respectively, via β+ and/or proton emission.
As a gas, the oxygen atom in H2O is hybridized via TP with the and DN with the As such, the H2O molecule perfectly fits with the four different energy levels (2 OH-peaks, 2 lone pair peaks) observed in the photo-electronic spectra of H2O (“no rabbit ears on the water”).64
As a liquid, H2O is a temperature-dependent mixture of the gas-phase hybridized form and a hybridized form in which the is linked with DN, and in which the TP is not linked intra-atomic with the but with the of a neighboring water molecule (Fig. 17B). Such an energetically favorable closure of the 4Hep-unit by a neighboring neutron is the basis for hydrogen bonds, hydrates, and e.g. crystal water.
As a solid (around zero degrees and lower), the predominant form of H2O will be the fully de-hybridized one, i.e. neutron (“hydrogen”) bonds between TP and the or of a neighboring water molecule, and neutron bonds between DN and the or of a neighboring water molecule. This fully de-hybridized form of the water molecule corresponds with expansion, which means a change in volume and, therefore, a change in density. Dissolved cations, but also the isotope with a square neutron at the and the isotope with an additional square neutron at the (see Fig. 18) will of course disrupt this hydrogen bond network, and might well be part of the reason behind the geometric variation in hexagonal-shaped snowflakes.
Fig. 19 Some illustrative carbon–oxygen combinations in the new model: (a) CO2; (b) H2CO3 and resonance in CO32−; (c) RCOOH and resonance in RCOO− (blue hooked arrow indicates hybridization). |
In carbon dioxide (CO2), the DN of each oxygen atom is bound to the hybridized carbon (TP + DP), the TP of each oxygen atom is bound to the hybridized carbon Upon dissolving of CO2 in water, carbonic acid (H2CO3) is formed. In this process, the two oxygen TP's become detached from the carbon forming two OH-groups, while the oxygen of the incoming H2O molecule becomes bound with its TP to the carbon and with its DN to the carbon DN.
In ketones, aldehydes and carboxylic acids the double-bonded oxygen atom is bound in the same way to carbon's and DN, whereas the anchor proton side of that C-atom is hybridized into the (TP + DP) form. Keto–enol tautomerism and chemical attack on ketones take place at whereby the oxygen-TP of the double-bonded oxygen becomes OH or O−. In carboxylic acids (RCOOH), the OH-group is bound with its oxygen–DN to the hybridized carbon (TP + DP). The oxygen–TP of this OH-group loses its hydrogen relatively easily because the oxygen–TP− can form a resonance system with the versatile oxygen–TP plus combination of the double-bonded oxygen. Finally, in phenols the OH-group is bound with its oxygen–DN to a DN of the benzene ring, after which the oxygen–TP− becomes part of the resonance system in alkaline solutions.
Fig. 20 Some illustrative nitrogen-oxygen combinations in the new model: (a) NO+/NO˙; (b) ; (c) HNO3. |
The has formed a bridgehead with its DN. The square proton of the has kept its non-activated low-energy electron, whereas the remaining DN of the together with the DN form two bonds with the hybridized nitrogen–(TP + DP). The third bond is formed between the oxygen–TP and the nitrogen–DN. In the compound NO+ the square has lost its electron.
In and NO2+,67 the nitrogen atom is the central atom with a bridge-headed and the square proton of the keeping its non-activated low energy electron or not. Each oxygen–TP is bound to the DN's of the bridge-headed , each oxygen–DN is bound to the hybridized nitrogen–(TP + DP).
A final illustrative example is the acid HNO3. This acid is a well-known octet rule disobeying compound (formally N5+ surrounded by 10 electrons) for which a Lewis structure has been developed. In the new atom model, the two double bonded oxygen atoms are bound with their DN to the hybridized nitrogen–(TP + DP) of the nitrogen atom and with their TP to the protons of the The oxygen of the OH-group bears an H-atom at its TP, and is bound with its DN to the nitrogen–DN (Fig. 20).
Fig. 21 Constellation of the main isotopes of fluorine (1s22s22p5) in the new model, including illustrative conversions. |
Closure of the latter unit by a neighboring neutron from an H2O or HF molecule gives rise to a hydrogen bond. With its n = 4, p = 3 at the anchor proton side and n = 3½, p = 4 at the anchor neutron side, follows the stability rules.
Radioisotope (t1/2 110 min.), a widely known component of PET-chemistry, lacks the square neutron in the at the anchor neutron side. It is produced by a (p, n) reaction on 68 the proton impact takes place at the DN, forming a and throws out the square neutron of the (last in, first out); decays via β+-emission back to (Fig. 21). Notably, (t1/2 162 nanoseconds, decay to 69) is the result of the impact at DN and throwing out the square neutron of the giving two with full energy protons; the IT to implies the fast shift of a neutron from the to this very neutron-deficient anchor neutron side as a temporarily better situation. Radioisotope produced by a (n, γ) reaction on 70 appears to be very instable (t1/2 11 s) with its n = 4, p = 4 at the anchor neutron side and its n = 5, p = 3 at the anchor proton side, and decays quickly to Atom (t1/2 65 s, produced by a (d, n) reaction on 71), bears two and decays to via β+-emission (conversion of a proton from one of the into a square neutron onto the other ); and lower are proton emitters.
Fig. 22 Constellation of the main isotopes of neon (1s22s22p6) in the new model, including one illustrative conversion. |
Fig. 22 also shows the constellation of the stable isotopes (0.27% abundance) and (abundance 9.25%), and of the instable (t1/2 17.3 s). In the atom, the has become a with a square neutron like in The atom bears two (one with a square neutron) at the anchor proton side, and two at the anchor neutron side (one with a square neutron). Neon isotopes both fit with the stability rules, with their n = 5, p = 4 at the anchor proton side and their n = 3, p = 3½ and n = 3½, p = 4, respectively, at the anchor neutron side. The atom is stable with n = 5½, p = 4 at the anchor proton side, and is, therefore, the second isotope that follows the special n = p + 1½ anchor proton side stability rule. As was the case with the extra neutron appears to remain as a square neutron in the lone pair, as because conversion of a neutron into a proton yielding does not occur. Again it is the other way around: radioactive decays to
In the short-living radioisotope , the at the anchor proton side is replaced by a During its production via a (p, n) reaction on 72 proton impact takes place at the TP of while the square neutron of the is thrown out. Atom decays back to via conversion of a proton from one of the into a square neutron onto the (β+-emission). Radioisotope (t1/2 1.7 s) bears two at the anchor proton side, and two at the anchor neutron side. It decays as a first step to instable by conversion of a proton of one of the below into a neutron at one of the above. The short-living radioisotopes (t1/2 37.1 s), and (t1/2 3.38 min) at the right side of will be dealt with in a forthcoming paper.
So in the new model also the last two elements of the 2s2,2p6-series, fluorine and neon, follow the remarkable regularity and consistency with respect to the stability or instability of the atoms. All stable isotopes Z = 3–10 appear to follow a strict n = p − ½ pattern at the anchor neutron side, and a n = p + 1 pattern at the anchor proton side; only for and the pattern is n = p + 1½. Any deviation from these patterns leads to conversion. Another regularity is that the EC-decay of radioisotope as well as the β+-decay of the nuclear medicine PET-isotopes and and of radioisotopes all imply conversion of a full energy proton into a square neutron. Even for and this is the case, although they seem to look like an exception: the newborn square neutron, temporarily bound as a square neutron to both PN's at the anchor neutron side, exchanges energy with the neighboring proton, leaving a or respectively, behind under formation of a DN.
Upon reaction with the carbon atom, the fact that the TP of fluorine strongly prefers covalent formation leads to subtle conflicts. Upon bond formation with the DP of carbon, the hybridized neutron (from DN or TP) has to be pushed aside. This forced re-hybridization will have its effect on the carbon skeleton. At the anchor neutron side of the carbon atom, bond formation with DN seems fine for the TP of F, but a is too much for the carbon–DN. The compromise will be a sort of with the hybridized (PN + DN)-units. Bond formation with hybridized PN will in case of a mono-fluorinated aliphatic compound suffer from easy elimination of HF in a process that resembles the keto–enol tautomerism for a carbonyl group. Finally, in the CF3-group (one F at the DP and two F's at the hybridized PN + DN), the TP of the carbon atom has become fully isolated and therefore exhibits more or less the same chemical behavior as the TP of F, which explains e.g. the chemistry of the CF3-group in trifluorotoluene (CF3–C6H5): in CF3–C6H5, the isolated TP of the carbon atom of the CF3-group, bound at the DP of the benzene ring, forces the benzene ring to re-hybridize, while the open neutron-deficient of the fluorine atoms of the CF3-group interacts with the DN-neutron of the neighboring carbon atoms of the benzene ring (the ortho positions). Notably, this explanation according to the new atom model, compiles in an elegant way the ‘double-bond no-bond’ resonance hypothesis, and the hypothesis wherein one of the three F-atoms of the CF3-group has formed a bond with one of the carbon atoms at the ortho-position of the benzene ring (so with F+ formation) (Fig. 23).74,75
The atom constellations arising from this new model not only provide an answer to the re-hybridizing power of fluorine, our primary objective. They also appear to be perfectly in accordance with the linear molecular geometry of beryllium, the trigonal planar molecular geometry of boron, and the tetrahedral molecular geometry of carbon, nitrogen and oxygen (including the special lone pairs of the latter two). In addition, the derived atom constellations follow a consistent pattern with respect to the stability of isotopes, the produced radioisotopes thereof, and the respective decay modes of the latter.
Other key topics are the new sound basis for covalent bond formation (formation of a “chemical” He-unit between a PN, DN, DP or TP-subunit with one of the subunits of the other atom), and the re-definition of the hydrogen bond (neutron bond between the TP-subunit of the atom and the neutron-deficient or of a neighboring molecule). Furthermore, the new model offers an improved answer to phenomena like the hybridization principle, inversion, chirality, resonance and the secret behind the chemical reactivity of the empty orbital of boron.
In a forthcoming “Part II” we will investigate whether the adjusted model still holds for the slightly heavier elements Z = 11–20, and if so, what the configurations of the atoms Na (Z = 11) through Ca (Z = 20) look like in the new approach. And, as a further matter, whether the new model can provide a genuine solution for the occurrence of multiple valencies of the elements P, S, and Cl, with special attention to the well-known “octet-rule violating” compounds H3PO4, H2SO4 and HClO4.
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