title: (1H-pyrazole-κN2)(2,2':6',2''-terpyridine-κ3N,N',N'')platinum(II) bis(perchlorate) nitromethane monosolvate.
abstract: The reaction between [PtCl(terpy)]·2H(2)O (terpy is 2,2':6',2''-terpyridine) and pyrazole in the presence of two equivalents of AgClO(4) in nitromethane yields the title compound, [Pt(C(3)H(4)N(2))(C(15)H(11)N(3))](ClO(4))(2)·CH(3)NO(2), as a yellow crystalline solid. Single-crystal X-ray diffraction shows that the dicationic platinum(II) chelate is square planar with the terpyridine ligand occupying three sites and the pyrazole ligand occupying the fourth. The torsion angle subtended by the pyrazole ring relative to the terpyridine chelate is 62.4 (6)°. Density functional theory calculations at the LANL2DZ/PBE1PBE level of theory show that in vacuo the lowest-energy conformation has the pyrazole ligand in an orientation perpendicular to the terpyridine ligand (i.e. 90°). Seemingly, the stability gained by the formation of hydrogen bonds between the pyrazole NH group and the perchlorate anion in the solid-state structure is sufficient for the chelate to adopt a higher-energy conformation.
authors: School of Chemistry, University of KwaZulu-Natal, Private Bag X01, Pietermaritzburg 3209, South Africa. akermanm@ukzn.ac.za
authors: Matthew
authors: M
authors: Akerman
authors: Kate
authors: K
authors: Akerman
authors: Deogratius
authors: D
authors: Jaganyi
authors: Desigan
authors: D
authors: Reddy
mesh_terms: D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D008024:Ligands; D015394:Molecular Structure; D009944:Organoplatinum Compounds / Q000737:chemistry*; D010472:Perchlorates / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: C562165:(1H-pyrazole-kappaN2)(2,2'-6',2'-terpyridine-kappa3N,N',N')platinum(II) bis(perchlorate) nitromethane; D008024:Ligands; D009944:Organoplatinum Compounds; D010472:Perchlorates; D010984:Platinum; C494474:perchlorate