Structure of platinum, zinc and cadmium 8-hydroseleno-L-quinolinates

Abstract

The Rh Vaska-type complexes, trans-[Rh(CO)(Cl)(YR3)] (Y=Group 15 atom; R=aryl or alkyl), analogues of the well-known Vaska's complex, trans-[Ir(CO)(Cl)(PPh3)], are well behaved model systems for various catalytic systems. They readily undergo a variety of reactions e.g., iodomethane oxidative addition, typically forming alkyl species as intermediates, e.g., [Rh(Cl)(CO)(CH3)(I)(YR3) ~], reductive elimination, substitution, insertion, etc. These Rh(I) complexes are easy to synthesize, and in conjunction with their Pd(II) and Pt(II) analogues, are potential homogeneous catalysts to also investigate structurally due to favorable thermal stability, while the CO and PR3 ligands render IR and 31 P NMR spectroscopy as powerful tools to evaluate different ligand effects. These complexes were used to quantify electronic and steric effects of different tertiary group 15 donor ligands (P, As, Sb) [1] , including PPh2Fc (ferrocenyldiphenylphosphine), and PTA (1,3,5-triaza-7-phosphaadamantane) enabling correlations between IR, 31 P NMR and X-ray crystallographic data. Selected four-, five-and six-coordinate pseudo Vaska-type complexes are presented, illustrating structural aspects and reactivity, equilibria and thermodynamics of these with regard to iodomethane oxidative addition/ ligand substitution.

Synthesis and structure of bismuth 8-quinoline-selenolate Bi(C9H6NSe)3

“…Our data for an X-ray diffraction study of the structure of complex 1 when compared to the structural data for bismuth 8-quinolinethiolate, Bi(C 9 H 6 NS) 3 (2) [13] permit us to clarify the effect of replacing the ligand atom S→Se on the molecular and crystal structure of these compounds and the state of the UEP in analogous complexes. Complex 1 was synthesized in 83.5% yield by the general scheme described in our previous work [6].…”

“…The arrangement of the atoms in the coordination nodes of studied 8-quinolinolates, 8-quinolinethiolates, and 8-quinolineselenolates of trivalent metals of Group III (Ga, In, Tl) and Group VIII (Co, Rh, Ir, Fe) corresponds to isomer B. The electronic structure of Group V p-elements in the incomplete valence state (As, Sb, Bi) accounts for the formation of the metal coordination polyhedron as isomer A in the 8-quinolinolates, 8-quinolinethiolates, and 8-quinolineselenolates of these metals [2,11,[13][14][15][16]. The crystal structures of these 8-quinolineselenolates, including bismuth 8-quinolineselenolate, Bi(C 9 H 6 NSe) 3 (1) studied in the present work, hold interest in comparative crystal chemistry for clarifying the role of the unshared electron pair (UEP) in formation of the metal coordination polyhedron.…”

Synthesis and crystal structure of bismuth 2-methyl-8-hydroselenoquinolinate

“…The crystal structure of complex I is formed by neutral asymmetric molecules in which bismuth atom is connected bidentatically (Se, N) with three 2-methyl-8-hydroselenoquinoline ligands. [2]. The influence of the unshared electron pair (E) of the V group partial valence p-elements (As, Sb, Bi) on formation of the above complexes is considered.…”

Structure of palladium quinoline-8-selenolate Pd(C9H6NSe)2

“…Consequently the main problem was the coordination possibility of selenium(II) as a ligand atom and the experimental determination of the lengths of the M-Se bonds in chelate compounds. Previously we established the molecular and crystal structures of the complexes Pt(C 9 H 6 NSe) 2 , Cd(C 9 H 6 NSe) 2 [2], Zn(C 9 H 6 NSe) 2 [3,4], In(C 9 H 6 NSe) 3 [5], and Sb(C 9 H 6 NSe) 3 [6].In the present work the synthesis and the results of the X-ray structural investigation of palladium(II) quinoline-8-selenolate Pd(C 9 H 6 NSe) 2 (1) are described. Since the crystal structures of palladium 8-mercaptoquinolinate (2) [7] and palladium 8-hydroxyquinolinate (3) [8] are known, a comparison of the structure of the five-membered metallocycles of one type and consideration of the dynamics of the experimentally found Pd-Se, Pd-S, Pd-O, and Pd-N bond lengths is possible.…”

“…Consequently the main problem was the coordination possibility of selenium(II) as a ligand atom and the experimental determination of the lengths of the M-Se bonds in chelate compounds. Previously we established the molecular and crystal structures of the complexes Pt(C 9 H 6 NSe) 2 , Cd(C 9 H 6 NSe) 2 [2], Zn(C 9 H 6 NSe) 2 [3,4], In(C 9 H 6 NSe) 3 [5], and Sb(C 9 H 6 NSe) 3 [6].…”