title: The pressure tunning Raman and IR spectral studies on the multinuclear metal carbyne complexes.
abstract: The Raman and infrared (IR) spectra of four tungsten metal carbyne complexes I, II, IV and V [Cl(CO)2(L)W[triple bond]CC6H4[triple bond](C[triple bond]CC6H4)n[triple bond]N[triple bond]C[triple bond]]2M (L = TMEDA, n = 0, M = PdI2 or ReCl(CO)3; L = DPPE, n = 1, M = PdI2 or ReCl(CO)3) were studied at high external pressure. Their pressure-induced phase transitions were observed near 20kbar (complexes I), 15 kbar (complexes II), 25 kbar (complex IV) and 30 kbar (complex V). The pressure-induced phase transition likely is first order in complex I and the pressure-induced phase transitions of complexes II, IV and V are mostly second order. The pressure sensitivities d nu/dp of nu(W[triple bond]C) are high in the low-pressure phase area and very low in the high-pressure phase area due to the pressure strengthening pi back-bonding from metal W to pi* orbital of C[triple bond]O in fragment Cl(CO)2(L)W[triple bond]C. The pressure strengthening metal pi back-bonding from metal Re or Pd to pi* orbital of C[triple bond]O or C[triple bond]N also happened to both of central metal centers of NCPd(I2)CN in complex I and NCReCl(CO)3CN in complex II.
authors.affiliation: State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China. zhcxu@pku.edu.cn
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Xu
authors.forename: Ian S
authors.initials: IS
authors.lastname: Butler
authors.forename: Andreas
authors.initials: A
authors.lastname: Mayr
mesh_terms: D002219:Carbamates / Q000737:chemistry*; D044367:Phase Transition; D011312:Pressure; D013055:Spectrophotometry, Infrared; D013059:Spectrum Analysis, Raman; D014414:Tungsten / Q000737:chemistry*
chemical_list: D002219:Carbamates; C004359:barban; D014414:Tungsten