Rhenium compounds hydride derivatives

A reversible deprotonation for a 17-electron hydride complex was shown for the stable cationic cobalt(II) hydride complex [CoH CH3C(CH2PPh2)3 (PEtj)]BPh4, yielding a presumed Co(0) neutral species. Although the latter species could not be isolated and fully characterized, it was shown that it can be reprotonated to yield the Co(II) hydrido species back [40]. Polyhydride complexes have also been shown to readily lose protons. Early examples have been provided by Walton on rhenium compounds, e.g. ReH5(PR3)3 derivatives [101], on the basis of electrochemical investigations. 

The chemistry of the metal carbonyl hydrides and metal carbonylates remained the principal research topic for Hieber until the 1960s. He mentioned in his account [25], that it was a particular pleasure for him that in his laboratory the first hydrido carbonyl complexes of the manganese group, HMn(CO)5 and HRe(CO)5, were prepared by careful addition of concentrated phosphoric acid to solid samples of the sodium salts of the [M(CO)5] anions, giving the highly volatile hydrido derivatives in nearly quantitative yield [45, 46]. In contrast to HCo(CO)4 and its rhodium and iridium analogues, the pentacarbonyl hydrido compounds of manganese and rhenium are thermally remarkably stable, and in... 

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