Triosmium clusters formed by oxidative addition and decarbonylation of 2-formylpyrrole: crystal structures of three triosmium clusters containing aromatic or nonaromatic heterocyclic ligands derived from pyrrole

• Published in: Organometallics Vol. 9; no. 1; pp. 6 - 12
• Main Authors: Day, Michael W, Hardcastle, Kenneth I, Deeming, Antony J, Arce, Alejandro J, De Sanctis, Ysaura
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01-01-1990
• Subjects: AZOLES; Chemistry; CLUSTER MODEL; COMPLEXES; Condensed matter: structure, mechanical and thermal properties; CRYSTAL STRUCTURE; DATA; DATA ANALYSIS; Exact sciences and technology; EXPERIMENTAL DATA; HETEROCYCLIC COMPOUNDS; INFORMATION; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; MATHEMATICAL MODELS; MEASURING INSTRUMENTS; MEASURING METHODS; NUCLEAR MODELS; NUMERICAL DATA; Organic chemistry; ORGANIC COMPOUNDS; ORGANIC NITROGEN COMPOUNDS; ORGANOMETALLIC COMPOUNDS; Organometalloidal and organometallic compounds; OSMIUM COMPLEXES; Physics; Preparations and properties; PYRROLES; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; TRANSITION ELEMENT COMPLEXES 400200 > Inorganic, Organic, & Physical Chemistry; Transition metals derivatives; Five membered ring; Nitrile; Molecular structure; Nitrogen heterocycle; Trinuclear complex; Organic ligand; Metallocycle; Transition metal Carbonyl Complexes; Experimental study; X ray diffraction; Hydrido complex; Osmium Organic compounds; Mu complex; Metal metal bond; Platinoid Complexes; Osmium Carbonyl Complexes; Crystalline structure
• ISSN: 0276-7333; 1520-6041
• DOI: 10.1021/om00115a002

The {mu}-acyl cluster (Os{sub 3}H({mu}{sub 2}-NHCH=CHCH=CCO)(CO){sub 10}) (1) is formed by oxidative addition of 2-formylpyrrole to (Os{sub 3}(CO){sub 10}(MeCN){sub 2}) in refluxing cyclohexane in the same manner as with other aldehydes. The crystals of 1 are triclinic, space group P{bar 1}, with cell dimensions a = 14.882 (2) {angstrom}, b = 15.626 (4) {angstrom}, c = 9.447 (3) {angstrom}, {alpha} = 107.39 (2){degree}, {beta} = 97.29 (2){degree}, {gamma} = 97.84 (2){degree}, and Z = 4. The structure was refined to R{sub w} = 0.034. The pyrrolylacyl ligand bridges two osmium atoms through the C and O atoms of the original formyl group. Thermal loss of two COs from 1 gives two isomers of the cluster (Os{sub 3}H{sub 2}({mu}{sub 3}-C{sub 4}H{sub 3}N)(CO){sub 9}) (2 and 3), isomer 2 converting to 3 thermally. Isomer 2, (Os{sub 3}H{sub 2}({mu}{sub 3}-NHCH=CHC=C)(CO){sub 9}), retains the NH bond and is directly related to the N-methyl analogue of 2, (Os{sub 3}H{sub 2}({mu}{sub 3}-MeNCH=CHC=C)(CO){sub 9}) (5), and closely related to the benzyne cluster (Os{sub 3}H{sub 2}(C{sub 6}H{sub 4})(CO){sub 9}), both of known X-ray structure. Cluster 2 converts to 3 by cleavage of N-H and Os-C bonds and with formation of C-H and Os-N bonds. Crystals of 3 are monoclinic, space group P2{sub 1}/c, with cell dimensions a = 11.308 (2) {angstrom}, b = 12.457 (2) {angstrom}, c = 15.384 (3) {angstrom}, {beta} = 123.59 (2){degree}, and Z = 8. The structure was refined to R{sub w} = 0.052. The structure is best defined by a model in which the {mu}{sub 3}-N=CHCH=CHC ligand is coordinated to one Os atom through a N atom and to the other two through a single C atom forming a {mu}{sub 2}-alkylidene bridge. The C{sub 4}N ring is formally nonaromatic and is oriented vertically to the metal plane.