Syntheses and NMR spectroscopic characterizations of the bimetallic complexes: (CO)5Mo(η-R2PXPR′2) Mo(CO)5 (R2,R′2 = Ph2, OCH2CMe2CH2O; X = O, NHCH2CH2NH); the structure of...

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Abstract

  • Title full: Syntheses and NMR spectroscopic characterizations of the bimetallic complexes: (CO)5Mo(η-R2PXPR′2) Mo(CO)5 (R2,R′2 = Ph2, OCH2CMe2CH2O; X = O, NHCH2CH2NH); the structure of (CO)5Mo- (η-Ph2POP(OCH2CMe2CH2O)) Mo(CO)5. Bimetallic complexes of the types (CO)5Mo(η-R2PXPR′2)Mo(CO) 5 (R2, R′2 = Ph2, OCH2CMe2CH2O; X = O, NHCH2CH2NH) have been synthesized by the reactions of Mo(CO)5(R′2PX) (X = Cl, Br) with either [Et3NH][Mo(CO)5(R2PO)] or Mo(CO)5(R2PNHCH2CH2NH2 ). These reactions provide a precise control over the coordination environment of the metals because the bridging, bidentate ligand is formed after the P-donor groups have been coordinated to the metal centers. The 13C and 31P NMR spectra of the complexes are discussed. The 13C NMR spectra of the complexes containing the R2 POPR′2 ligands varies significantly with the nature of the R2 and R′2 groups. The resonances that are coupled to P are apparent quintets (A portion of an AXX′ spin system) for. the symmetrical complexes and doublets (A portion of an AXY spin system with no A-Y coupling) for the unsymmetrical complexes. The X-ray crystal structure of (CO)5Mo(η-Ph2POP(OCH2CM2 CH2O))Mo(CO)5 has been determined. The complex crystallizes in the monoclinic space group P21/c (a 8.792(2), b 33.946(5), c 10.762(1) Å; β 104.02(1)°; V 3116.3(6) Å3; Z = 4). The structural data suggest that the Ph2P group is a better electron donor (poorer electron acceptor) than is the P(OCH2CMe2CH2O) group and are consistent with NMR spectroscopic results. The P(OCH2CMe2CH2O) ring is in a chair conformation, which is slightly flattened at the P, with Mo(CO)5 group in the equatorial position. © 1988.
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    Author List

  • Gray GM; Watt W
  • Start Page

  • 149
  • End Page

  • 161
  • Volume

  • 349
  • Issue

  • 1-2