76380-95-5Relevant academic research and scientific papers
Prepaparion, Properties, and Reactions of Metal-Containing Heterocycles, XCI. Insertion of Activated Alkynes and Sulfur into the P-P Bond of Diphosphamolybdacyclopropanes
Lindner, Ekkehard,Kneissle, Wilfried,Fawzi, Riad,Steimann, Manfred,Mayer, A. Hermann,Gierling, Karlheinz
, p. 973 - 982 (2007/10/03)
The insertion of alkynes ZCCZ (2a-i) a), Et (b), (nPR (c), iPr (d), nBu (e), tBu (f), neo-Pent (g), cyc-Hex (h); Z = CF3 (i)> into the P1-P2 bond of the diphosphamolybdacyclopropane (1) (Mes = 2,4,6-trimethylphenyl) results in the formation of the diphosphamolybdacyclopentenes (3a-i).According to an X-ray structural analysis, 3a crystallizes in the space group P21/c with the mesityl function at P2 and the cyclopentadienyl fragment at the metal atom on the opposite side of the planar five-membered ring.The same orientation is found in solution by NMR experiments (NOE; 2D 1H, 13C HECTOR).Kinetic investigations confirm that the rate constants decrease in the sequence R = Me > Et > nPr > isoProp > Cy > nBu > neoPent > tBu.The second-order reaction and the strongly negative activation entropy which was determined in the case of the reaction 1 + 2e -> 3e are consistent with a nucleophilic attack of P2 at one of the triply bonded carbon atoms of the alkyne.The reaction of 3a, h with sulfur affords the diastereomeric compounds (4a,h).An X-ray structural analysis of the heterocycle 4h, which crystallizes in the space group , shows the presence of the enantiomeric pair SR/RS.The reaction of 1 with alkynes is hindered if this heterocycle is oxidized by sulfur to give (5).Further reaction of 5 with sulfur leads to the ring-expanded heterocyclic intermediate (6) which crystallizes in the space group .The five-membered ring in 6 has an envelope conformation.Upon thermally induced cleavage of the P2S2Mes fragment from 6 the three-membered ring (7) is formed as the final product. - Keywords: Molybdenum heterocycles / P-P bonds / Activated alkynes / Sulfur / Insertion reactions
Preparation, properties, and structural studies of molybdenum and tungsten complexes with [Ph2P(S)C(S)NR]- (R = Me, Ph) or Ph2PS- ligands. X-ray structure analysis of Mo(CO)2(η5-C5H5)[Ph 2P(S)C(S)NPh]
Ambrosius,Van Hemert,Bosman,Noordik,Ariaans
, p. 2678 - 2685 (2008/10/08)
M(CO)3(η5-C5H5)Cl (M = Mo, W) reacts with Ph2P(S)C(S)N(H)R (R = Ph, Me) and a base to yield three different products depending on reaction time and temperature. At room temperature complexes of composition M(CO)2(η5-C5H5)[Ph 2P(S)C(S)NR] are obtained, in which the ligands are coordinated by both sulfur atoms. At higher temperature mixtures are obtained of M(CO)2(η5-C5H5)[Ph 2P(S)C(S)NR] (M = Mo, R = Ph, Me; M = W, R = Me), in which the ligand is coordinated through S(C) and N, and M(CO)2(η5-C5H5)(η 2-SPPh2) (M = Mo, W). The last complexes can also be prepared from M(CO)3(η5-C5H5)Cl in a direct reaction with SPPh2H and Et3N. M(CO)3(PPh3)2Cl2 (M = Mo, W) reacts with 2 equiv of Ph2P(S)C(S)N(H)Ph in the presence of a base to form M(CO)2(PPh3)[Ph2P(S)C(S)NPh]2, in which the ligands show a dynamic behavior with respect to the coordinating mode. The starting complexes react with SPPh2H and Et3N to M(CO)2(PPh3)(η2-SPPh2) 2. Under similar conditions Mo(CO)4Cl2 gives Mo(CO)3(η2-SPPh2)2. The complexes are characterized by means of elemental analyses, infrared spectroscopy, and 1H and 31P NMR spectroscopy. The X-ray structure analysis of Mo(CO)2(η5-C5H5) [Ph2P(S)C(S)NPh] is presented: a = 10.390 (4) A?, b = 14.328 (5) A?, c = 9.602 (3) A?, a = 73.02 (2)°, β = 108.49 (2)°, and γ = 112.39 (2)° in space group P1 and Z = 2.
Molybdenum and Tungsten Complexes with Side-on Co-ordinated SPPh2-Ligands. X-Ray Crystal Structure Determination of Mo(CO)2(PPh3)(η2-SPPh2)2CH2Cl2
Ambrosius, Huub P. M. M.,Noordik, Jan H.,Ariaans, Gerry J. A.
, p. 832 - 833 (2007/10/02)
M(CO)3Cl(η5-C5H5) and M(CO)3(PPh3)2Cl2 (M = Mo, W) react with SPPh2H and Et3N to give M(CO)2(η5-C5H5)(η2-SPPh2) and M(CO)2(PPh3)(η2-SPPh2)2, respectively; an X-ray crystal structure determination of Mo(CO)2(PPh3)(SPPh2)2 reveals a 7-co-ordinate pseudopentagonal bipyramidal geometry for the molybdenum atom with an almost planar configuration for the sulphur and phosphorus atoms.
