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Ruthenium‐Cluster‐Mediated Activation of All Bonds of a Methyl Group of 6,6′‐Dimethyl‐2,2′‐bipyridine and 2,9‐Dimethyl‐1,10‐phenanthroline: Transformation of the Latter into a 2‐Alkenyl‐9‐methyl‐1,10‐phenanthroline Ligand
Author(s) -
Cabeza Javier A.,
del Río Ignacio,
MartínezMéndez Lorena,
Miguel Daniel
Publication year - 2006
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200500813
Subject(s) - ruthenium , chemistry , carbyne , stereochemistry , crystallography , square pyramid , hydrogen bond , methyl group , ring (chemistry) , bipyridine , atom (system on chip) , group (periodic table) , molecule , medicinal chemistry , crystal structure , catalysis , biochemistry , organic chemistry , carbene , computer science , embedded system
The treatment of [Ru 3 (CO) 12 ] with 6,6′‐dimethyl‐2,2′‐bipyridine (Me 2 bipy) or 2,9‐dimethyl‐1,10‐phenanthroline (Me 2 phen) in THF at reflux temperature gives the trinuclear dihydride complexes [Ru 3 (μ‐H) 2 (μ 3 ‐L 1 )(CO) 8 ] (L 1 =HCbipyMe 1 a , HCphenMe 1 b ), which result from the activation of two CH bonds of a methyl group. The hexa‐, hepta‐, and pentanuclear derivatives [Ru 6 (μ 3 ‐H)(μ 5 ‐L 2 )(μ‐CO) 3 (CO) 13 ] (L 2 =CbipyMe 2 a , CphenMe 2 b ), [Ru 7 (μ 3 ‐H)(μ 5 ‐L 2 )(μ‐CO) 2 (CO) 16 ] (L 2 =CbipyMe 3 a , CphenMe 3 b ), and [Ru 5 (μ‐H)(μ 5 ‐C)(μ‐L 3 )(CO) 13 ] (L 3 =bipyMe 4 a , phenMe 4 b ) can also be obtained by treating 1 a and 1 b with [Ru 3 (CO) 12 ]. Compounds 2 a and 2 b have a basal edge‐bridged square‐pyramidal metallic skeleton with a carbyne‐type C atom capping the four Ru atoms of the pyramid base. The structures of 3 a and 3 b are similar to those of 2 a and 2 b , respectively, but an additional Ru atom now caps a triangular face of the square‐pyramidal fragment of the metallic skeleton. The most interesting feature of 2 a , 2 b , 3 a , and 3 b is that their carbyne‐type C atoms were originally bound to three hydrogen atoms in Me 2 bipy or Me 2 phen and, therefore, they arise from the unprecedented activation of all three CH bonds of C‐bound methyl groups. The pentanuclear compounds 4 a and 4 b contain a carbide ligand surrounded by five Ru atoms in a distorted trigonal‐bipyramidal environment. They are the products of a series of processes that includes the activation of all bonds (three CH and one CC) of organic methyl groups, and are the first examples of complexes having carbide ligands that arise from C‐bonded methyl groups. The alkenyl derivatives [Ru 5 (μ 5 ‐C)(μ‐ p ‐MeC 6 H 4 CHCHphenMe)(CO) 13 ] ( 5 b ), [Ru 5 (μ‐H)(μ 5 ‐C)(μ‐ p ‐MeC 6 H 4 CHCHphenMe)( p ‐tolC 2 )(CO) 12 ] ( 6 b ), and [Ru 5 (μ‐H)(μ 5 ‐C)(μ‐PhCHCHphenMe)(PhC 2 )(CO) 12 ] ( 7 b ) have been obtained by treating 4 b with p ‐tolyl‐ and phenylacetylene, respectively. Their heterocyclic ligands contain an alkenyl fragment in the position that was originally occupied by a methyl group. Therefore, these complexes are the result of the formal substitution of an alkenyl group for a methyl group of 2,9‐dimethyl‐1,10‐ phenanthroline.