An Acidity Scale of Tetrafluoroborate Salts of Phosphonium and Iron Hydride Compounds in [D2]Dichloromethane
作者:Tianshu Li、Alan J. Lough、Robert H. Morris
DOI:10.1002/chem.200601484
日期:2007.4.27
pK(CD(2)Cl(2)) values for 15 other hydride or dihydrogen complexes of the iron group elements and of diethyl ether were also placed on this scale. The crystal structures of [Fe(CO)3H(PCy(2)Ph)2][BF4] and [Fe(CO)3(PCy(2)Ph)2] revealed that the trans-oriented, bulky, unsymmetrical phosphane ligands distort the equatorial plane of the complexes. The acidity of iron carbonyl hydrides is an important feature of
Aza- and Oxadithiolates Are Probable Proton Relays in Functional Models for the [FeFe]-Hydrogenases
作者:Bryan E. Barton、Matthew T. Olsen、Thomas B. Rauchfuss
DOI:10.1021/ja8057666
日期:2008.12.17
and oxaditiholate show enhanced rates of proton transfer between solution and the terminal site on one Fe center. The results are consistent with the heteroatom of the dithiolate serving a gating role for both protonation and deprotonation. The pK(a) of the transiently formed ammonium (pK(CD(2))(Cl(2)) 5.7-8.2) or oxonium (pK(CD(2))(Cl(2)) -4.7-1.6) regulates the proton transfer. As a consequence, only