Structural and spectroscopic study of a five-coordinate rhodium(I) complex (η-1,5-cyclooctadiene)(η-2, 6-diallylpyridine,N)rhodium (1+) with two different and unusual di-μ-chloro-bis[dichlorodimethylstannate](2−) anions. Crystal structures of [Rh(C8H12)-(C11H13N)]2[{SnCl3(CH3)2}2] · 2CH2C12 and [Rh(C8H12)-(C11H13N)]2[{SnCl3(CH3)2}2]

The preparation and structures of a five-coordinate rhodium(I) complex with 2,6-diallylpyridine (DAP) and cyclooctadiene (COD) ligands with two different {SnCl₃(CH₃)₂}₂]^2? anions are described, including IR and¹H NMR data. The crystals of the title compounds are both triclinic P¯1: C₄₂H₆₂Cl₆N₂Rh₂Sn₂·2CH₂Cl₂ (1)a=12.200(4),b=13.016(4),c=9.402(2) Å,α=93.92(1),β=100.67(1), γ=115.03(2)°,V _c =1311.2(7) ų,Z= 1,R=0.0312 for 3321 independent observed reflections; C₄₂H₆₂Cl₆N₂Rh₂Sn₂ (2)a=12.187(3),b=12.851(3),c=7.752(2) Å,α=90.15(1),β=101.22(1), γ=73.29(1)°,V _c =1138.8(5) ų,Z=1,R=0.0429 for 4117 independent observed reflections. In both structures the cationic rhodium has a trigonal-bipyramidal environment with theN-pyridine and one double bond of the COD ligand in axial positions and the two allylic double bonds together with the other double COD bond in equatorial positions. Much more interesting are the structures of the anionic parts, which show a different unsymmetrical dimerization through two chlorine bridges. The tin coordination polyhedra, which assume a distorted trigonal-bipyramidal geometry in the monomeric units, achieve an octahedral shape. There is a simple correlation between the Me-Sn-Me angle value and the longest Sn-Cl bond distance.