Title

Synthesis and characterization of ReCl(H < inf> 2 )(AsMePh < inf> 2 ) < inf> 4 , a classical hydride complex; reexamination of ReCl(H < inf> 2 )(PMePh < inf> 2 ) < inf> 4 and theoretical calculations on model compounds

Document Type

Article

Publication Date

7-2-2001

Abstract

The synthesis of ReCl(H2)(AsMePh2)4 is reported and verified on the basis of 1H NMR and FAB-MS. The minimum T1 time for the metal-bonded hydrogen atoms was determined to be 44 ms (-78 °C) and 89 (-48 °C) ms at 200 and 400 MHz, respectively. From this minimum T1 time, and, allowing for contributions from other nuclei to the relaxation, a metal-bonded H to H atom distance of 1.57 Å can be assessed. The complex is reversibly oxidized at a potential E1/2(ox) = +0.07 V. The JHD coupling in the related ReCl(HD)(AsMePh2)4 compound was at 3.3 Hz. These data for ReCl(H2)(AsMePh2)4 suggest that this molecule contains classical hydrides, and interpretations on T1 and X-ray data published previously for ReCl(H2)(PMePh2)4 suggest that this molecule contains a very long metal-bonded H-H interaction of 1.39 Å. Theoretical calculations on model compounds ReCl(H2)(XR3)4 (X = P, As; R = H, Me) give virtually identical average dH-H values of 1.5 (XH3) and 1.63 (XMe3) Å.

Publication Title

Inorganic Chemistry

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