[Raman and infrared spectral studies of tungsten organometallic carbyne complex at high external pressure].

ABSTRACT

The Raman and infrared spectra of complex [Cl(CO)2 (DPPE) W identical to CC6H4C identical to CC6H4NC]2 Re Cl(CO)3 (DPPE = bis (diphenylphosphino) ethane, (Ph)2PCH2CH2P(Ph)2) were measured at high external pressure (up to about 50 kbar). The pressure induced phase transition was observed near 30 kbar. The pressure dependence d nu/dp of nu (W identical to C) at the low-pressure phase is a little high (0.59 cm-1.(kbar)-1) and is very low (0.04 cm-1.(kbar)-1) at the high-pressure phase. It shows that the pi-backbonding from W to pi*--orbital of CO is strengthened at the high external pressure in fragment Cl(CO)2 (DPPE) W identical to C; The bond intensity and the force constant of W identical to C and nu (W identical to C) are decreasing; This effect compete with the normal increasing nu (W identical to C) on compression.