X-ray crystallographic, NMR and kinetic correlation of selected Pt^IIcomplexes

Abstract

Cd(CN)2 has Cu20-lil'e structure, where two dirn11ond-like 3D frrnneworks based on tetrahedral Cd2+ rn1d bridging CN-rn•e interpeneu•ated each other. Cd(CN)2•G clathrates were preprn•ed on the idea tl1at one JJ-rnnework in Cd(CN)2 was replaced with bulky orgmlic guest molecules such as cyclohexrn1e, CCL;, etc. X-ray study on Cd(CN) 2 cyclo-hexrn1e clatl1rate revealed tl1at the host lattice has tl1e dirnnond-lil'e 3D frrn11ework rn1d guest cyclohexrn1e molecule is trapped in empty space of the host lattice. However, two questions remained. One was about ordering of tl1e bridging CN-. X-ray showed orientation of tl1e CN-was in disordered state. However, it has been believed that CN-in Cd(CN) 2 is ordered. 1 13Cd MAS NlVIR revealed that tl1e CN-was in disordered state in Cd(CN)2•G rn1d even in Cd(Ci\l)2. Another question was about stmctme rn1d motional behavior of the cyclohexrn1e. X-ray showed only dif-f11se electron density mound tl1e center of the cavity. 2H-NMR powder patterns indicated that the cyclohexane was in rapid random isou•opic motion at room temperatUie rn1d tllis isotTOpic motion rn1d the inversion of the cyclohexrn1e 1ing begrn1 to freeze in lower temperature region.

trans-Bis(3,5-diaza-1-azonia-7-phosphaadamantane-κP)bis(thiocyanato-κS)palladium(II) bis(thiocyanate)

“…In the past few years, numerous 1,3,5-triaza-7-phosphaadamantane (PTA) complexes exhibiting catalytic activity have been reported (Alyea et al, 1993;Joo  et al, 1996;Darensbourg et al, 1997Darensbourg et al, , 1999. PTA is a neutral air-stable aliphatic phosphine with a small steric demand (Daigle et al, 1998;Otto & Roodt, 2001a). The potentially tetradentate PTA ligand coordinates to the metal centre only through the P atom, as observed in all of the metal±PTA complexes characterized to date (Cambridge Structural Database; Allen, 2002).…”

Packing effects on the geometry of neutral platinum(II) complexes due to solvate molecules: the structure of trans-dichlorobis(triphenylarsine)platinum(II)

“…This paper is devoted to describing the geometry of the neutral complex trans-[PtCl 2 (AsPh 3 ) 2 ], as observed in four different crystallographic environments. This Pt II complex was prepared in a systematic study of syntheses and reactivity of bis-tertiary arsine complexes (Watkins, 1970;Roodt et al, 1995;Otto & Roodt, 1996. The structures of the four compounds, i.e.…”