73440-16-1Relevant academic research and scientific papers
Preparation and solution behavior of diphosphinepalladium nitrite complexes
Moser, Jennifer A.,Stockland Jr., Robert A.,Anderson, Gordon K.
, p. 1329 - 1332 (2008/10/08)
Diphosphinepalladium nitrite complexes of the type [Pd(NO2)2L2] (L2 = dppm, dppe, dppp) have been prepared by treatment of [PdCl2(CH3CN)2] with silver nitrite, followed by addition of the appropriate diphosphine. The nitrite complexes are fluxional in solution at 298 K, but on cooling to 220 K signals due to three species could be detected. These have been assigned to the N-bonded, the O-bonded, and the mixed coordination compounds. Treatment of [PdCl2(dppe)] with two equivalents of TlPF6, followed by addition of Na15NO2, produced [Pd(15NO2)2(dppe)], whose 31P NMR spectrum allowed identification of the three isomers. The analogous platinum complex [Pt(NO2)2(dppe)] exists as a single isomer, which is static at 298 K, and a 15NO2-labeling experiment indicated that it contains N-bonded nitrite ligands. (C) 2000 Elsevier Science Ltd.
Synthesis of new CO complexes of palladium
Feltham,Elbaze,Ortega,Eck,Dubrawski
, p. 1503 - 1510 (2008/10/08)
The palladium(II) complexes Pd(NO2)2L2 (L = PPh3, PMePh2, PMe2Ph, PEt3) react with CO to form Pd4(CO)5L4. These reaction products have been characterized by IR and 31P, 1H, and 13C NMR spectroscopy. Pd4(CO)5(PPh3)4 crystallized in the monoclinic space group C2/c with Z = 4, a = 24.957 (5) ?, b = 16.138 (3) ?, c = 17.758 (3) ?, and β = 103.47 (2)°. The palladium atoms are at the corners of a distorted tetrahedron in which five of the six edges are bridged by the carbonyl ligands. The unbridged edge has a Pd-Pd distance of 3.209 (1) ?, indicating the absence of a metal-metal bond. The average bonding Pd-Pd distances are 2.753 (1) and 2.758 (13) ?. The average Pd-P distance is 2.318 (2) ?, and the average Pd-C-Pd angle is 82.0°. Pd(NO2)2(PEt2Ph)2 and PdCl(NO2)(PEt2Ph)2 react with CO to form the novel Pd(I) dimer Pd2(CO)Cl2(PEt2Ph)3, which was also structurally characterized by X-ray crystallography. The compound crystallized in the monoclinic space group P21/a with Z = 4, a = 20.041 (3) ?, b = 11.353 (3) ?, c = 19.920 (5) ?, and β = 129.16 (1)°. The molecule is dimeric with a Pd-Pd bond and is the first example of a semibridging carbonyl ligand in palladium complexes. Pd2 has roughly square-planar geometry with two phosphines, one chloride, and Pd1 comprising its coordination sphere. One phosphine, one chloride, Pd2, and the carbonyl ligand comprise the coordination sphere of Pd1. The semibridging carbonyl produces severe distortion in the coordination geometry of both Pd1 and Pd2. Some important distances and angles include Pd1-Pd2 = 2.6521 (3) ?, Pd1-C = 1.874 (3) ?, Pd2-C = 2.110 (3) ?, and Pd1-C-Pd2 = 83.3 (1)°.
