Synthesis and structural characterization of chloro(2,2′;6′,2″-terpyridine)platinum(II) trichloro(dimethylsulfoxide)platinate(II). Density functional analysis of model molecules

✍ Scribed by Renzo Cini; Alessandro Donati; Rovena Giannettoni

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 161 KB
• Volume: 315
• Category: Article
• ISSN: 0020-1693
• DOI: 10.1016/s0020-1693(01)00317-6

✦ Synopsis

The addition of a solution of terpy (2,2%;6%,2¦-terpyridine) to a solution of cis-[PtCl 2 (dmso) 2 ] (dmso, dimethylsulfoxide) in acetone, at 25°C, brought to the formation of [PtCl(terpy)][PtCl 3 (dmso)] (1), as a high yield crystalline red powder, within 12 h. Single crystals of 1 suitable for X-ray diffraction studies were obtained from dmso solution and contain chains of [PtCl(terpy)] 2 2 + dimers (Pt-Pt, 2.338(1) A , ) with a Pt•••Pt inter-dimer contact distance of 3.419(1) A , . The [PtCl(terpy)] + moieties have a head-to-tail disposition throughout the chains. The [PtCl 3 (dmso)] -anions do not have any short internuclear contact but are associated with the chains of cations via (terpy)C-H•••Cl and (terpy)C-H•••O hydrogen bond type interactions. The [PtCl(terpy)] + moiety has been simulated via the density functional methods at the B3LYP/LANL2DZ level (6-31G** for Cl), applied to model systems such as [PtCl(NH 2 ) 3 ] 2 -, [Pt(H 2 O) 4 ] 2 + , [PtCl(H 2 O) 3 ] + , [PtCl(NH CH-CH N-C( CH 2 )-CH NH)] + , [{PtCl(NH 2 ) 3 }{Pt(H 2 O) 4 }], [{PtCl(H 2 O) 2 (NH 2 )}{PtCl(NH 2 ) 3 ] 2 -, [PtCl(H 2 O) 3 ] 2 2 + , [PtCl(NH CH-CH N-C( CH 2 )-CH NH)] 2 2 + . The computed structure for [PtCl(NH CH-CH N-C( CH 2 )-CH NH)] + reproduces well the corresponding moiety of the [PtCl(terpy)] + cation; for instance, the computed Pt-Cl distance is 2.305 A , , just 0.006 A , smaller than the value found for 1. The optimization of the [{PtCl(NH 2 ) 3 }{Pt(H 2 O) 4 }] neutral molecule which consists of a dianion and a dication brought to a dimer whose Pt-Pt distance is 3.079 A , , much smaller than twice the Van der Waals radius for Pt (1.7-1.8 A , ).