Potential energy surfaces for Tc+H sub 2 and Ru+H sub 2 reactions

Journal Article · Fri Dec 15 04:00:00 EST 1989 · Journal of Chemical Physics; (USA)

DOI:https://doi.org/10.1063/1.457243· OSTI ID:5113984

Balasubramanian, K; Wang, J Z ^[1]

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1. Department of Chemistry, Arizona State University, Tempe, Arizona 85287-1604 (US)

Potential energy surfaces of 12 electronic states of TcH{sub 2} and RuH{sub 2} are obtained using a complete active space MCSCF (CASSCF) followed by multireference singles + doubles configuration interaction calculations (MRSDCI). The {sup 6}{ital S} ground state of Tc has to surmount a barrier of 40 kcal/mol to insert into H{sub 2} while the {sup 5}{ital F} ground state of Ru inserts into H{sub 2} with a much smaller barrier of 8.5 kcal/mol. The excited {sup 6}{ital D}, {sup 4}{ital D}, and doublet states of Tc atom insert into H{sub 2} spontaneously. The ground state of TcH{sub 2} is a linear {sup 6}{Sigma}{sup +}{sub {ital g}} state arising from the {sup 6}{ital S} state of the Tc atom, while the ground state of RuH{sub 2} is of bent equilibrium geometry with {sup 3}{ital A}{sub 2} symmetry. A nearly degenerate bent state of {sup 3}{ital B}{sub 1} symmetry also exists for RuH{sub 2}. The bent minima of TcH{sub 2} are at least 0.9 eV above the linear {sup 6}{Sigma}{sup +}{sub {ital g}} ground state of TcH{sub 2}. The ground state of RuH{sub 2} is 35 kcal/mol more stable than Ru({sup 3}{ital F}) + H{sub 2} while the {sup 6}{Sigma}{sup +}{sub {ital g}} ground state of TcH{sub 2} is 27 kcal/mol more stable than Tc({sup 6}{ital S})+H{sub 2}. All the bent states of TcH{sub 2} and RuH{sub 2} are ionic exhibiting strong M{sup +}H{sup {minus}} polar bonds. The M--H bonds are made of {ital dsp} hybrid bonds as evidenced from Mulliken population analyses.

• OSTI ID: 5113984
• Journal Information: Journal of Chemical Physics; (USA), Journal Name: Journal of Chemical Physics; (USA) Vol. 91:12; ISSN JCPSA; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
CHEMICAL BONDS
CHEMICAL REACTION KINETICS
CONFIGURATION INTERACTION
ELECTRONIC STRUCTURE
ELEMENTS
HYDRIDES
HYDROGEN
HYDROGEN COMPOUNDS
KINETICS
METALS
NONMETALS
PLATINUM METALS
REACTION KINETICS
REACTIVITY
REFRACTORY METAL COMPOUNDS
RUTHENIUM
RUTHENIUM COMPOUNDS
RUTHENIUM HYDRIDES
TECHNETIUM
TECHNETIUM COMPOUNDS
TECHNETIUM HYDRIDES
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS