An attractive cis-effect of hydride on neighbor ligands: Experimental and theoretical studies on the structure and intramolecular rearrangements of Fe(H) sub 2 (. eta. sup 2 -H sub 2 )(PEtPh sub 2 ) sub 3

Journal Article · Wed Jun 06 00:00:00 EDT 1990 · Journal of the American Chemical Society; (USA)

DOI:https://doi.org/10.1021/ja00168a030· OSTI ID:6880093

Van Der Sluys, L S; Huffman, J C; Caulton, K G ^[1]; Eckert, J; Hall, J H; Kubas, G J; Vergamini, P J ^[2]; Eisenstein, O; Jackson, S A ^[3]; Koetzle, T F ^[4]

---

1. Indiana Univ., Bloomington (USA)
2. Los Alamos National Laboratory, NM (USA)
3. Centre de Paris-Sud, Orsay (France)
4. Brookhaven National Laboratory, Upton, NY (USA)

The compound of formula FeH{sub 4}(PEtPh{sub 2}){sub 3} has been established by neutron diffraction to possess the structure and linkage cis,mer-Fe(H{sub 2})(PEtPh{sub 2}){sub 3}, and thus be generally similar in structure to cis,mer-Fe(H){sub 2}(N{sub 2})(PEtPh{sub 2}){sub 3}, whose structure has been determined by X-ray diffraction. The Fe-hydride distances in Fe(H){sub 2}(PEtPh{sub 2}){sub 3} are 1.538 (7) {angstrom} (trans to H{sub 2}) and 1.514 (6) {angstrom} (trans to PEtPh{sub 2}), and the Fe-H (of H{sub 2}) distances are 1.607 (8) and 1.576 (9) {angstrom}. The H-H distance in coordinated dihydrogen is 0.821 (10) {angstrom}, but the H-H bond adopts an orientation unique among structurally characterized octahedral H{sub 2} complexes: staggered with respect to the cis Fe-P and Fe-H axes. Vibrational frequencies of the Fe(H){sub 2}(H{sub 2}) substructure have been measured by difference inelastic neutron scattering spectroscopy. Neutron scattering also reveals the low-frequency rotational tunneling splitting, allowing estimation of the height of the torsional barrier for coordinated H{sub 2} rotating about its midpoint ({approximately}1 kcal/mol).

• DOE Contract Number: AC02-76CH00016
• OSTI ID: 6880093
• Journal Information: Journal of the American Chemical Society; (USA), Vol. 112:12; ISSN 0002-7863
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
HYDRIDES
STRUCTURAL CHEMICAL ANALYSIS
DATA ANALYSIS
EXPERIMENTAL DATA
LIGANDS
MEASURING INSTRUMENTS
MEASURING METHODS
ORGANOMETALLIC COMPOUNDS
VIBRATIONAL STATES
DATA
ENERGY LEVELS
EXCITED STATES
HYDROGEN COMPOUNDS
INFORMATION
NUMERICAL DATA
ORGANIC COMPOUNDS
400201* - Chemical & Physicochemical Properties