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Protonic–Hydridic Bifunctionality: The Protonic (2‐Aminoethyl)dimethylphosphane Ligand in Nitrosyl Tungsten Hydride Complexes
Author(s) -
Chen Zilu,
Timokhin Ivan,
Schmalle Helmut W.,
Fox Thomas,
Blacque Olivier,
Berke Heinz
Publication year - 2009
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.200900443
Subject(s) - chemistry , ligand (biochemistry) , hydride , medicinal chemistry , trimethylphosphine , stereochemistry , tungsten , crystal structure , crystallography , metal , organic chemistry , biochemistry , receptor
The chemistry of nitrosyl tungsten hydrides bearing the (2‐aminoethyl)dimethylphosphane ligand (edmp) with an acidic NH functionality was studied. Such complexes were targeted by applying the reaction of WCl 3 (NO)(CH 3 CN) 2 with edmp, which gave [WCl 2 (NO)(η 2 ‐edmp) 2 ][Cl] ( 1a ) and [WCl 2 (NO)(η 2 ‐edmp) 2 ][BPh 4 ] ( 1b ). Complex 1b was treated with Zn to produce [W(H)(Cl)(NO)(η 2 ‐edmp) 2 ][BPh 4 ] ( 2b ). Subsequent attempts with the use of WCl(NO)[P(OMe) 3 ] 4 and edmp as starting materials produced {W(NO)(η 2 ‐edmp) 2 [P(OMe) 3 ]}[Cl] ( 3a ) at 85 °C and [W(H)(Cl)(NO)(η 2 ‐edmp) 2 ][Cl] ( 2a ) at 120 °C. Substitution of the P(OMe) 3 ligand in {W(η 2 ‐edmp) 2 (NO)[P(OMe) 3 ]}[BPh 4 ] ( 3b ) with CO afforded [W(CO)(η 2 ‐edmp) 2 (NO)][BPh 4 ] ( 4b ). Complex 4b was treated withNaHBEt 3 , resulting in a dihydride product [W(CO) trans ‐(η 1 ‐edmp) 2 (H) 2 (NO)]Na ( 4c ). The chlorido complexes containing one η 2 ‐edmp ligand WCl(NO)(η 2 ‐edmp)(PMe 3 ) 2 ( 5a ), WCl(NO)(η 2 ‐edmp)(CO)(PMe 3 ) ( 6a ), WCl(NO)(η 2 ‐edmp)[P(OMe) 3 ] 2 ( 5b ), and WCl(NO)(CO)(η 2 ‐edmp)[P(OMe) 3 ] ( 6b ) were prepared and treated with NaHBEt 3 to obtain the corresponding hydride species WH(NO)(η 2 ‐edmp)[P(OMe) 3 ] 2 ( 8b ), WH(NO)(CO)(η 2 ‐edmp)(PMe 3 ) ( 7a ), and WH(NO)(CO)(η 2 ‐edmp)[P(OMe) 3 ] ( 7b ). The initially formed WH(NO)(η 2 ‐edmp)(PMe 3 ) 2 ( 8a ) was spontaneously transformed into the amide complex W(NO)(CO)(NHCH 2 CH 2 PMe 2 )(PMe 3 ) ( 11a ) with loss of H 2 . The anionic dihydride products [W(H) 2 (η 1 ‐edmp)(NO)L 2 ]Na [L = PMe 3 ( 9a ) and L = PMe 3 ( 9b )] were produced from 7a and 7b by the reaction with NaHBEt 3 . Hydride 8b turned out to be the most stable hydride complex in the given series. NMR spectroscopic experiments and deuterium labeling showed that 8b coexists in equilibrium with corresponding dihydrogen amide complex 10b . The structures of compounds 1a , 2b , 3a , 4b , 5b , 6a , and 6b were studied by single‐crystal X‐ray diffraction.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)