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Crystal structure of (HRh(P(O-i-C/sub 3/H/sub 7/)/sub 3/)/sub 2/)/sub 2/: a neutron diffraction study

Journal Article · · Inorg. Chem.; (United States)
DOI:https://doi.org/10.1021/ic50220a040· OSTI ID:6342129
A neutron diffraction study of (HRh(P(O-i-C/sub 3/H/sub 7/)/sub 3/)/sub 2/)/sub 2/ confirmed the square-planar coordination geometry inferred from spectroscopic data and accurately placed the hydride ligands at bridging positions. At 112.4/sup 0/K, the crystal lattice was triclinic, of space group P anti 1, with a = 12.084 (3) A, b = 13.505 (6) A, c = 9.540 (2) A, ..cap alpha.. = 97.49 (2)/sup 0/, ..beta.. = 105.18 (1)/sup 0/, ..gamma.. = 116.15 (2)/sup 0/, V/sub c/ = 1074.4 A/sup 3/, and Z = 1. The Rh-Rh distances were 2.65 (1) A, and the Rh-H distances were 1.808 (14) A with H-Rh-H and Rh-H-Rh angles of 85.9 (5) and 94.1 (4)/sup 0/, respectively. With an only slightly expanded P-Rh-P angle of 94.7 (4)/sup 0/, near 90/sup 0/ average H-Rh-P angles, and near coplanarity of the H/sub 2/Rh/sub 2/P/sub 4/ system, the square-planar coordination geometry about each rhodium atom was established unequivocally. The planar Rh/sub 2/H/sub 2/ system is rectangular with 2.65- and 2.46-A diagonals. Two four-center (Rh/sub 2/H/sub 2/) two-electron bonds are responsible for the framework bonding in the diameter. The net Mulliken bond order for the direct Rh-Rh interaction is positive but very small whereas those for Rh-H are large, nearly 0.5, as indicated by a molecular orbital analysis.
OSTI ID:
6342129
Journal Information:
Inorg. Chem.; (United States), Journal Name: Inorg. Chem.; (United States) Vol. 20:6; ISSN INOCA
Country of Publication:
United States
Language:
English