Chromium hydride shifts

The i>3 Region. This mode will be ir-active for a linear or bent M-H-M array. Accordingly, low temperature spectra for all 12 combinations of Et4N+ and PPN+ with hydrido- and deuterio-bridged Cr, Mo, and W anions were examined. For spectra recorded at 8°K, the H.D isotope shift allows positive identification of the mode in the four chromium salts and two tungsten hydrides... 

The anionic hydrido carbonyls have been much studied because of their intermediacy in catalytic processes like the water gas shift reaction, reduction of organic substances, and other reactions. Thus chromium group hydrides [HM(CO)4PR3] are highly efficient H-transfer agents and for reactions with alkyl halides a reactivity order was established cii-[HW(CO)4PR3] > m-[HCr(CO)4PR3] > [HW(CO)5]... 

---