Premium
N ‐Heterocyclic Phosphenium, Arsenium, and Stibenium Ions as Ligands in Transition Metal Complexes: A Comparative Experimental and Computational Study
Author(s) -
Burck Sebastian,
Daniels Jörg,
GansEichler Timo,
Gudat Dietrich,
Nättinen Kalle,
Nieger Martin
Publication year - 2005
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.200400538
Subject(s) - carbene , chemistry , reactivity (psychology) , transition metal , ion , crystallography , yield (engineering) , covalent bond , metal , stereochemistry , medicinal chemistry , catalysis , materials science , organic chemistry , medicine , alternative medicine , pathology , metallurgy
Reaction of 2‐chloro‐1,3,2‐diazaarsolenes and ‐diazaphospholenes with Tl[Co(CO) 4 ] gives instable complexes of type [Co(ER 2 )(CO) 4 ] which decarbonylated to yield [Co(ER 2 )(CO) 3 ]. Spectroscopic and X‐ray diffraction studies revealed that the tetracarbonyl complexes can be formulated as ion pair for E = P and as covalent metalla‐arsine for E = As, and the tricarbonyl complexes as carbene‐like species with a formal E=Co double bond. A similar reactivity towards Tl[Co(CO) 4 ] was also inferred for 1,3,2‐diazastibolenes although the products were not isolable and their constitution remained uncertain. Evaluation of structural and computational data suggests that the weak and polarized Co–As bond in [Co(AsR 2 )(CO) 4 ] can be characterized as an “inverse” M→L donor‐acceptor bond. The computational studies disclosed further η 2 (EN)‐coordination of the EN 2 C 2 heterocycle as an alternative to the formation of a carbene‐like structure for [Co(ER 2 )(CO) 3 ]. The η 2 ‐complex is less stable for E = P but close in energy for E = As and more stable than the carbene‐like complex for E = Sb.