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Synthese und NMR.‐Spektren von neuartigen Lanthanoid‐Kobalt‐Sandwichkomplexen
Author(s) -
Kläui Wolfgang
Publication year - 1977
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19770600418
Subject(s) - chemistry , lanthanide , cyclopentadienyl complex , proton nmr , crystallography , molecule , cationic polymerization , nmr spectra database , cobalt , fermi contact interaction , chemical shift , spectral line , stereochemistry , ion , inorganic chemistry , catalysis , polymer chemistry , paramagnetism , organic chemistry , physics , quantum mechanics , astronomy
Synthesis and NMR. Spectra of Novel Lanthanide‐Cobalt Sandwich Compounds The reaction of [(C 5 H 5 )Co{P(O)(OR) 2 } 2 {P(OH)(OR) 2 }] ( 3 , R = CH 3 , C 2 H 5 ) with lanthanide(III) compounds yields the cationic trinuclear complexes [{(C 5 H 5 )Co[P(O)(OR) 2 ] 3 } 2 Ln] ⊕ X ⊖ ( 2 , R = CH 3 , C 2 H 5 ; Ln = La, Eu, Pr; X = BF 4 , BPh 4 ). According to thermogravimetric and NMR. studies these compounds do not contain additional coordinated water molecules. It is therefore supposed that the central lanthanide ion has a regular sixfold coordination of phosphoryl ligands. The 31 P‐ and 1 H‐NMR. spectra of 2 (R = CH 3 ; Ln = La, Eu, Pr) and 3 are discussed. It can be shown that the Fermi contact shift as well as the coordination shift make significant contributions to the observed lanthanide induced shift of the cyclopentadienyl signal.The dominating influence of the Fermi contact interaction on the 31 P chemical shift is in accord with theoretical considerations and comparable experimental values. The temperature dependence of the proton chemical shifts of 2 (R = CH 3 ; Ln = Eu) is also discussed.