AMINO SUBSTITUENTS AS ELECTRON-DONORS IN CLUSTERS
JOURNAL OF ORGANOMETALLIC CHEMISTRY. Bd. 426. H. 1. 1992 S. 87 - 97
Erscheinungsjahr: 1992
ISBN/ISSN: 0022-328X
Publikationstyp: Zeitschriftenaufsatz
Doi/URN: 10.1016/0022-328X(92)83163-C
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Inhaltszusammenfassung
In clusters, in which an alkyne RCCR' is added to an (mu-3-RP)Fe3(CO)9 fragment, normally both carbon atoms of the alkyne group are engaged in interaction with the metal constituents. We have now found that with aminoalkynes RCCN(Et)2 the amino-substituted carbon atom of the alkyne fragment normally eludes this complete integration into the cluster by formation of a C = N double bond. These observations may be reduced to the statement that an amino group connected to a skeletal carbon atom of...In clusters, in which an alkyne RCCR' is added to an (mu-3-RP)Fe3(CO)9 fragment, normally both carbon atoms of the alkyne group are engaged in interaction with the metal constituents. We have now found that with aminoalkynes RCCN(Et)2 the amino-substituted carbon atom of the alkyne fragment normally eludes this complete integration into the cluster by formation of a C = N double bond. These observations may be reduced to the statement that an amino group connected to a skeletal carbon atom of a cluster increases the effective number of skeletal electrons in such a way, that the observed structures correspond to the ones, which, on the basis of Wade's rules, should ensue from an increased number of skeletal electrons. Exceptions from this statement are found if potentially conjugative groups, i.e. CO, are connected to the other carbon atom of the aminoalkyne constituent. These general propositions are documented here for two isomeric clusters (iPrP)Fe3(CO)9(MeCCNEt2) (2 and 3) and one cluster with the composition (iPrP)Fe3(CO)10(MeCCNEt2), (4) by spectroscopic and X-ray structural data. » weiterlesen» einklappen