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

Journal Article · Fri Jun 01 04:00:00 EDT 1990 · Journal of Chemical Physics; (USA)

DOI:https://doi.org/10.1063/1.458305· OSTI ID:6879442

Das, K K; Balasubramanian, K ^[1]

---

1. Department of Chemistry, Arizona State University, Tempe, AZ (USA)

Geometries, potential-energy surfaces (PES), and some one-electron properties of 12 electronic states of two second row transition metal dihydride ions, namely, TcH{sup +}{sub 2} and RuH{sup +}{sub 2} are calculated using complete active space multiconfiguration self-consistent field (MCSCF) followed by multireference single- and double-excitation configuration interaction (MRSDCI) methods. The ground-state Tc{sup +} ({ital a}{sup 7}{ital S}, {ital d}{sup 5}{ital s1}) ion does not insert into H{sub 2}. The {sup 5}{ital B}{sub 2} ground state of TcH{sup +}{sub 2} with geometry {ital r}{sub {ital e}}=1.59 A, {theta}{sub {ital e}}=49.5{degree} is formed by the spontaneous insertion of Tc{sup +}({ital a}{sup 5}{ital D}, 4{ital d}{sup 6}) into H{sub 2}. The quartet-state Ru{sup +} ({ital a}{sup 4}{ital F}) ion arising from the 4{ital d}{sup 7} configuration inserts spontaneously into H{sub 2} to form the ground state ({sup 4}{ital A}{sub 2}) of RuH{sup +}{sub 2} with {ital r}{sub {ital e}}=1.678 A and {theta}{sub {ital e}}=29.2{degree}. RuH{sup +}{sub 2} in the ground state is better described as a complex of Ru{sup +} ({ital a}{sup 4}F) with H{sub 2}. The energies of formation of the ground states of TcH{sup +}{sub 2} and RuH{sup +}{sub 2} from their dissociated counterparts are calculated as 22.4 and 21.2 kcal/mol, respectively. All the sextet-state PES's of RuH{sup +}{sub 2} and some of the quintet-state surfaces (namely, {sup 5}{ital A}{sub 1}, {sup 5}{ital A}{sub 2}, and {sup 5}{ital B}{sub 1} ) of TcH{sup +}{sub 2} contain large barriers for insertion. The high-spin linear stationary states of both TcH{sup +}{sub 2} and RuH{sup +}{sub 2} are more stable than the low-spin linear states. The polarity of the metal--H bond in the ground state of TcH{sup +}{sub 2} is found to be opposite to that in RuH{sup +}{sub 2}.

• DOE Contract Number: FG02-86ER13558
• OSTI ID: 6879442
• Journal Information: Journal of Chemical Physics; (USA), Journal Name: Journal of Chemical Physics; (USA) Vol. 92:11; 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
ATOMIC IONS
CATIONS
CHARGED PARTICLES
CHEMICAL BONDS
CHEMICAL REACTION KINETICS
CONFIGURATION INTERACTION
ELECTRONIC STRUCTURE
ELEMENTS
HYDRIDES
HYDROGEN
HYDROGEN COMPOUNDS
IONS
KINETICS
NONMETALS
REACTION KINETICS
REFRACTORY METAL COMPOUNDS
RUTHENIUM COMPOUNDS
RUTHENIUM HYDRIDES
RUTHENIUM IONS
SELF-CONSISTENT FIELD
TECHNETIUM COMPOUNDS
TECHNETIUM HYDRIDES
TECHNETIUM IONS
TRANSITION ELEMENT COMPOUNDS