Synthesis of a series of Pd(ii) complexes of the type [Pd(1,10-phen)(SRF)2]: an interesting case of solvatomorphism

Abstract

In this work, the formation of non-solvated crystalline structure [Pd(1,10-phen)(2,3,5,6-S-C₆F₄H)₂] 1 (1,10-phen = 1,10-phenanthroline) and three different crystalline solvatomorphs [Pd(1,10-phen)(2,3,5,6-S-C₆F₄H)₂]·S (S = C₆H₆2, C₆H₆Cl 3 and C₆H₆Br 4) is described. In addition, the formation of crystalline solvate [Pd(1,10-phen)(2,3,4,5,6-S-C₆F₅)₂]·C₆H₆Br (5) is described for comparison purposes with the former compounds. In this case, we are interested in getting deep into the knowledge of the phenomena of solvatomorphism. Therefore, we performed computational studies to determine the involved energetics features (π⋯π stacking energy phen⋯phen) of structures 1–5 to evaluate their stability associated with this interaction. In addition, graphical 2D plots of Hirshfeld surfaces were used to analyze the interactions involved in the non-solvated tecton and the solvatomorphic and solvate species. According to single-crystal X-ray diffraction results, solvatomorphs 2 and 3 are isostructural; however, 4 is non-isomorphic, despite only the difference of the solvated molecule occluded. In the case of 4 and 5, an increase in the H/F ratio in the tecton leads to the formation of different packing patterns.