Reactions of the polyhydride complex ReH7(dppe) (dppe = Ph2PCH2CH2PPh2) with pyridine-2-carboxylic acid, 1-isoquinolinecarboxylic acid, 2-hydroxy-6-methylpyridine and 2-mercaptoquinoline. Synthesis and structural characterization of seven-coordinate monohydrido complexes of rhenium(III)

Article abstract of DOI:10.1016/0277-5387(96)00039-3

The thermal reactions of ReH₇(dppe) (dppe = Ph₂PCH₂CH₂PPh₂) with pyridine-2-carboxylic acid (Hpic), 1-isoquinolinecarboxylic acid (Hisoquin), 2-hydroxy-6-methylpyridine (Hmhp) and 2-mercaptoquinoline (Hmq) in refluxing benzene afforded the monohydridorhenium(III) species ReH(L)₂(dppe) [L = pic (1a), isoquin (1b), mhp (1c), mq (1d)]. While analogous complexes have been prepared previously from ReH₇(PPh₃)₂ in the case of L = pic, isoquin and mhp, the reactions between ReH₇(PPh₃)₂ and the ligands 2-hydroxyquinoline and 2-mercaptoquinoline are dependent on the choice of reaction solvent; the rhenium hydride complexes ReH₄(L)(PPh₃)₂ (L = hq or mq) and ReH(hq)₂ (PPh₃)₂ have been isolated in a pure state. ¹H and ³¹P NMR spectral measurements on the seven-coordinate species 1a - d show that these compounds are stereochemically rigid at room temperature. The solution structures are in accord with the solid state structures of 1c and 1d, as determined by X-ray crystallography. Copyright