Thermodynamics for the clustering of ammonia onto Pb sup + in the gas phase

Journal Article · Thu Sep 07 00:00:00 EDT 1989 · Journal of Physical Chemistry; (USA)

DOI:https://doi.org/10.1021/j100355a044· OSTI ID:7108533

Gleim, K L; Guo, B C; Keesee, R G; Castleman, Jr, A W ^[1]

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1. Pennsylvania State Univ., University Park (USA)

Equilibrium constants together with the enthalpy, entropy, and Gibbs free energy changes were determined for the gas-phase stepwise addition reactions of up to four ammonia molecules onto the Pb{sup +} ion. Standard enthalpy changes of -28.3, -19.2, -13.0, and -10.7 kcal/mol and entropy changes of -23.3, -27.3, -22.0, and -24.8 cal/K {center dot} mol were measured for the first, second, third, and fourth steps of the clustering, respectively. These results, along with earlier ones for the clustering of ammonia onto Li{sup +}, Na{sup +}, K{sup +}, and Rb{sup +}, provide evidence concerning the structure and types of bonding in metal ion-ammonia clusters. Since the binding in Pb{sup +}NH{sub 3} and Pb{sup +}(NH{sub 3}){sub 2} is much stronger than that expected by electrostatic calculation, partial covalent interaction of Pb{sup +} with NH{sub 3} is likely in these two clusters. Theoretical calculations were also carried out with the Sakur-Tetrode equation to determine the contributions of the translational, rotational, and vibrational components to the entropy change for each of the above clustering reactions.

• OSTI ID: 7108533
• Journal Information: Journal of Physical Chemistry; (USA), Vol. 93:18; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
54 ENVIRONMENTAL SCIENCES
AMMONIA
CHEMICAL REACTIONS
LEAD IONS
CLUSTER MODEL
DATA ANALYSIS
EXPERIMENTAL DATA
MEASURING INSTRUMENTS
MEASURING METHODS
THEORETICAL DATA
THERMODYNAMIC PROPERTIES
CHARGED PARTICLES
DATA
HYDRIDES
HYDROGEN COMPOUNDS
INFORMATION
IONS
MATHEMATICAL MODELS
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NUCLEAR MODELS
NUMERICAL DATA
PHYSICAL PROPERTIES
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Organic
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540110
400800 - Combustion
Pyrolysis
& High-Temperature Chemistry