In:
Zeitschrift für Naturforschung B, Walter de Gruyter GmbH, Vol. 40, No. 7 ( 1985-7-1), p. 975-980
Abstract:
Dinuclear complexes of the type {(CO) 4 Mn}μ-E(CF 3 ) 2 , μ-Y {Mn(CO) 4 } (E = P, As; Y = Cl, Br, I; SR, SeR , TeR , with R varying over a wide range of inductive, mesomeric and steric properties) have been investigated by 55 Mn NMR spectroscopy. The NMR signals cover the range of -415 to -1450 ppm (relative to aqueous KMnO 4 ); half-widths are between 400 and several thousand Hz. The 55 Mn - 31 P one-bond coupling is usually unresolved, an exception being the complex with two P(CF 3 ) 2 bridges [J(MnP) = 152 Hz], The temperatur gradient for δ( 55 Mn) is 1.2 ppm/deg. Shielding of the 55 Mn nucleus is discussed with respect to δ and π bonding effects and the polarizability (electronegativity) of the bridging functions. With Y = SP(CF 3 ) 2 and SeP(CF 3 ) 2 , five-ring system s with two inequivalent manganese sites are formed, which give rise to two 55 Mn NMR signals, the sharper resonance for the site of higher symmetry [Mn{P(CF 3 ) 2 } 2 ] lying at -1750 ppm.
Type of Medium:
Online Resource
ISSN:
1865-7117
,
0932-0776
DOI:
10.1515/znb-1985-0721
Language:
English
Publisher:
Walter de Gruyter GmbH
Publication Date:
1985
detail.hit.zdb_id:
2078109-X
detail.hit.zdb_id:
124635-5
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