The Crystal and Molecular Structure of Pentane-2,4-dionato-(2,3,5,6-tetrahepto-2,3-dicarbomethoxo[2.2.1]bicycloheptadiene)rhodium(I), Rh(C₅H₇O₂) (C₇H₆(CO₂CH₃)₂)

Abstract

Chem. 53,2707Chem. 53, (1975. The crystal and molecular structures of pentane-2,4-dionato-(2,3,5,6-tetrahapto-2,3-dicarbomethoxo[2.2.~]bicycloheptadienerhodium~, Rh(C5J3702)(C7H6(C02CH3)2), have been measured by single crystal X-ray diffraction. The orange crystals are monoclinic, space group P2'/c, Z = 4, a = 9.245(4), b = 9.003(4), c = 21.680(15) A, = 113.41(5)". The calculated and observed densities are 1.645 and 1.642(5) respectively. Intensity data were collected on a Syntex P I diffractometer and a full matrix least squares refinement on 3010 observed reflections leads to a conventional R = 0.0660. The structure can be considered as a roughly square planar arrangement of ligands around the rhodium atom composed of two a-ketoenolate oxygen atoms (Rh-0, 2.037(5) and 2.025(5) A) and the centers of the two ethylenic groups. The Rh-C distances for the olefin group attached to the two carbomethoxo groups, 2.117(8), 2.108(8) A, appear to be slightly larger than those for the other olefinic group, 2.087(7), 2.082(6), and the corresponding C=C distances of 1.375 (10) . On a recueilli les donnks dYintensit6 avec un diffractometre Syntex P I et la structure affinCe par la m6thode des moindres carres (matrice complete) pour 3010 r6flexions observks a conduit a une valeur de R conventionnelle de 0.0660. On ~e u t consid6rer aue la structure com~orte en premiere approximation un arrangement plan carr6 des ligands autour deI 'atome de rhodium; cet arrangement comporte deux atomes d'oxygene du a-ckto6nolate (Rh-0,2.037(5) et 2.025(5) A) et le centre de deux groupes BthylCniques. I1 semble que les distances Rh-C (2.117(8) et 2.108(8) A) du groupe olkfinique attach6 aux deux groupes carbom6thoxo sont 16gerement plus larges que celles (2.087(7) et 2.082(6) A) de l'autre groupe ol6finique. Les distances C=C correspondantes,

Crystal and molecular structure of a one-dimensionally stacked binuclear rhodium(I) complex containing a tetradentate dibenzoylhydrazido ligand

“…Bond distances within the metallocycle suggest substantial electron delocalization over the NCO portion of the ring. The N-C distance of 1.309 (16) Á and the C-0 distance of 1.255 (15) Á are both shorter than expected single-bond lengths. 19 On the other hand, the N-N distance of 1.398 (18) A is essentially a single-bond value.…”

Crystal and molecular structure of a five-coordinate rhodium(I)-diene complex and the correlation of structural parameters with carbon-13 nuclear magnetic resonance shifts

“…Clearly geometry is allimportant, since the effect is not observed when the same diene is present in the square-planar complex pentane-2,4-dionato(2,3,5,6-n4-2,3-dicarbomethoxybicyclo[2.2.1]heptadiene)rhodium(I), 6, where the Rh-0 bond lengths (2.037 (5), 2.025 (5) A) are normal. 35 In the /3-keto enolate group some small angular distortions are observed which we assume are caused by packing considerations. The main ring of the /3-keto enolate group (0(1)C(1)C(2)C(3)0(2)) makes a dihedral angle of 7°with the RhO(l)0(2) plane and is bent away from the axial C=C group.…”

“…C( 7) 132 (1) 468.2 (7) 133.6 ( 6) 41 (2) C( 8) 19 (1) 546.8 (9) 83.6 ( 7) 55 (3) C (9) -144 (1) 528. 4 125.1 (5) 35 (2)…”

“…Apart from the lengthening of the C=C distances to 1.448 (10) and 1.390 (11) A from 1.343 (3) A in free norbornadiene, the distances and angles observed in the norbornadiene group do not differ significantly from those found in free norbornadiene,36,37 in a norbornadiene-palladium complex,38 or in the rhodium complex, 6. 35 The packing of the molecules in the crystal can be described in terms of a double chain along the c direction. Pairs of molecules in the two chains are related by the inversion center and contact is between the hydrogen atoms of the norbornadiene group on one molecule and a fluorine atom and oxygen atom of the /3-keto enolate group and a hydrogen of the norbornadiene group on the other molecule.…”