HEATS OF FORMATION FOR BORON COMPOUNDS BASED ON QUANTUM CHEMICAL CALCULATIONS

2010 ◽  
Vol 09 (06) ◽  
pp. 1009-1019
Author(s):  
JIAHENG ZHANG ◽  
SHIQIAN WEI ◽  
CHAOZHU MAO ◽  
LIANG CHEN ◽  
HAIXIANG GAO ◽  
...  

We have calculated the heats of formation at 298.15 K of series of boron compounds including H , N , O , F , Cl atoms using the atomization enthalpies analysis based on eleven quantum chemical calculations. The majority of calculated values are in excellent agreement with available experiment values and Gaussian-n methods perform more accurate evaluations than other approaches. As with the existing literature, the following calculations of the heats of formation of borides containing light atoms are recommended as accurate values: ΔfHG2,298 (BH) = 442.731 kJ·mol-1, ΔfHG2,298 (BF3) = -1135.749 kJ·mol-1, the deviations are respectively 0.031 kJ·mol-1 and 0.251 kJ·mol-1. Furthermore, ab initio calculations of heats of formation of chlorinated boron compounds also show good accuracy and comparisons with previous thermodynamics data are made.

1996 ◽  
Vol 03 (01) ◽  
pp. 399-403 ◽  
Author(s):  
G. GANTEFÖR ◽  
H. HANDSCHUH ◽  
H. MÖLLER ◽  
CHIA-YEN CHA ◽  
P.S. BECHTHOLD ◽  
...  

The photoelectron spectra of [Formula: see text] clusters are compared to the results of quantmn-chemical ab-initio calculations (n=2-9) and to the predictions of the shell model. The shell model yields qualitative assignments of the dominant features in the spectra to photoemission from occupied electronic shells. These correspond to the exact quantitative assignments to transitions into various electronic states of the neutral clusters according to the quantum-chemical calculations. The photoelectron spectra of [Formula: see text] and [Formula: see text] clusters exhibit certain similarities to the Ag data in agreement with the basic idea of the shell model.


2004 ◽  
Vol 69 (6) ◽  
pp. 1169-1194 ◽  
Author(s):  
Jürgen Schatz

In this short review the application of ab initio quantum chemical calculations on calixarenes and calixarene complexes is highlighted. The main focus lies on results obtained mainly during the last 2-3 years. A review with 92 references.


2020 ◽  
Vol 16 (2) ◽  
pp. 93-103 ◽  
Author(s):  
Piotr Kawczak ◽  
Leszek Bober ◽  
Tomasz Bączek

Background: Pharmacological and physicochemical classification of bases’ selected analogues of nucleic acids is proposed in the study. Objective: Structural parameters received by the PCM (Polarizable Continuum Model) with several types of calculation methods for the structures in vacuo and in the aquatic environment together with the huge set of extra molecular descriptors obtained by the professional software and literature values of biological activity were used to search the relationships. Methods: Principal Component Analysis (PCA) together with Factor Analysis (FA) and Multiple Linear Regressions (MLR) as the types of the chemometric approach based on semi-empirical ab initio molecular modeling studies were performed. Results: The equations with statistically significant descriptors were proposed to demonstrate both the common and differentiating characteristics of the bases' analogues of nucleic acids based on the quantum chemical calculations and biological activity data. Conclusion: The obtained QSAR models can be used for predicting and explaining the activity of studied molecules.


2021 ◽  
Author(s):  
Soichi Shirai ◽  
Shinji Inagaki

Practical strategies for suppressing Si–C cleavage during the polycondensation of organosilanes were presented based on ab initio quantum chemical calculations of model compounds.


2009 ◽  
Vol 50 (2) ◽  
pp. 195-200 ◽  
Author(s):  
Yu. V. Frolov ◽  
A. V. Vashchenko ◽  
A. G. Mal’kina ◽  
B. A. Trofimov

2020 ◽  
Author(s):  
Sopanant Datta ◽  
Taweetham Limpanuparb

<p>This article presents theoretical data on geometric and energetic features of halobenzenes and xylenes. Data were obtained from <i>ab initio</i> geometry optimization and frequency calculations at HF, B3LYP, MP2 and CCSD levels of theory on 6-311++G(d,p) basis set. In total, 1504 structures of halobenzenes, three structures of xylenes and one structure of benzene were generated and processed by custom-made codes in Mathematica. The quantum chemical calculation was completed in Q-Chem software package. Geometric and energetic data of the compounds are presented in this paper as supplementary tables. Raw output files as well as codes and scripts associated with production and extraction of data are also provided.</p>


2019 ◽  
Author(s):  
Kridtin Chinsukserm ◽  
Wanutcha Lorpaiboon ◽  
Peerayar Teeraniramitr ◽  
Taweetham Limpanuparb

<p>This article presents theoretical data on geometric and energetic features of halogenated compounds of cyclopropane (∆) and ethene (C=C), imine (C=N), methylphosphine (C=P), iminophosphine (N=P), diazene (N=N) and diphosphene (P=P). The data were obtained from <i>ab initio</i> geometric optimization and frequency calculations at HF, B3LYP, MP2 and CCSD levels of theory on 6-311++G(d,p) basis set. Input structures were generated by shell scripts and run by Q-Chem quantum chemical package. The output files were processed to extract geometric and energetic information by Wolfram Mathematica.</p>


2016 ◽  
Vol 18 (4) ◽  
pp. 2548-2563 ◽  
Author(s):  
Stefanie A. Mewes ◽  
Jan-Michael Mewes ◽  
Andreas Dreuw ◽  
Felix Plasser

Exciton analyses of high-level quantum-chemical computations for poly(paraphenylene vinylene) reveal the nature of the excitonic bands in PPV oligomers.


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