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Complexes of Zinc(II) with N ‐Imidazolyl‐ and N ‐Pyrazolylpyrimidine Donor Ligands: Synthesis, Crystal Structures, and Theoretical Study
Author(s) -
Cañellas Pablo,
Torres Marta,
Bauzá Antonio,
Cánaves María M.,
Sánchez Kika,
Cabra María I.,
GarcíaRaso Angel,
Fiol Juan J.,
Deyà Pere M.,
Molins Elies,
Mata Ignasi,
Frontera Antonio
Publication year - 2012
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201200379
Subject(s) - chemistry , hexacoordinate , tetracoordinate , crystallography , crystal structure , zinc , stacking , ligand (biochemistry) , stereochemistry , non covalent interactions , molecule , ab initio quantum chemistry methods , metal , coordination complex , atom (system on chip) , ab initio , hydrogen bond , computer graphics (images) , receptor , organic chemistry , silicon , computer science , planar , embedded system , biochemistry
The synthesis and crystal‐structure determination of three zinc(II) complexes with 2‐(1 H ‐imidazol‐1‐yl)pyrimidine(imipyr) and 2‐(1 H ‐pyrazol‐1‐yl)pyrimidine (pyrapyr) ligands are reported. Complexes [Zn(imipyr) 2 Cl 2 ] ( 1 ) and[Zn(pyrapyr) 2 Cl 2 ] ( 2 ) are mononuclear systems, and [Zn 2 (pyrapyr) 2 (Cl) 4 ] ( 3 ) is a dinuclear complex with two chlorido bridging ligands. In complex 3 , the coordination numbers of the two differently coordinated Zn ions are four and six. All complexes were characterized by X‐ray crystallography. A high‐level theoretical study was performed to rationalize the interesting noncovalent interactions observed in the solid state. All three structures show a peculiar π stacking, which is characterized by the absence of π–π ring‐plane overlapping. In this slipped stacking mode, the rings are antiparallely displaced, and alternating C ··· N interactions are established. Moreover, complex 3 forms infinite 1D columns by means of double anion–π interactions with pyrapyr. The atoms‐in‐molecules (AIM) theory proposed by Bader was used to characterize the anion–π and π–π interactions observed in the solid state. A high‐level ab initio study (RI‐MP2/def2‐TZVP level of theory) was performed to analyze the anion–π binding affinity of the pyrapyr ligand coordinated to the transition metal atom. Finally, a CSD search demonstrates that the structure of 3 is quite unique, because dinuclear Zn complexes that contain one tetracoordinate and one hexacoordinate metal center are rare, whereas this combination is common in trinuclear, linear complexes. With bridging chlorido ligands, this simultaneous tetra‐ and hexacoordination is unprecedented.