ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
A thorough IR and 1H-, 13C-, 31P-, 183W-NMR spectroscopic, and X-ray structural study was carried out on complexes of the type trans, trans-[WH(CO)2(NO)(PR3)2], (R = Et, Me, Ph, i-PrO, MeO, and PhO). Linear correlations could be found between Tolman's parameter X and v(CO), v(WH), v(NO), δ(13C) (CO), as well as 1n(k), k being the H/D exchange rate constant for the hydride in CD3OD. The 1J(183W,31P), 2J(31P,1H), and 2J(31P,13C) as well as the 1J(183W,1H) values are related to the electronegativity of the R groups on the phosphorus ligands. This is also indicated by EHT calculations of s-orbital populations of appropiate W model complexes. The X-ray structures of [WH(CO)2(NO)(PR3)2] (R = Me, Ph, and MeO) were determined. Minor differences were observed in the W—P bond lenghts and in the P—W—P and C—W—C angles. No obvious relationship between X-ray data and spectroscopic parameters could be found. All three structures reveal a bending of both the CO and PR3 ligands towards the hydride atom. The total octahedral distortion is remarkably constant (25.6, 29.4, and 27.0° tilt, respectively), although the ligands individually are very different. This is attributed to redistribution of π-electron density between CO and PR3 groups toward the central W-atom in the three complexes.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19910740606
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