Matrix Isolation and Electronic Structure of Di- and Tridehydrobenzenes

2010 ◽  
Vol 63 (7) ◽  
pp. 1013 ◽  
Author(s):  
Michael Winkler ◽  
Wolfram Sander
Keyword(s):  
Electronic Structure ◽  
Quantum Chemical ◽  
Structural Information ◽  
Matrix Isolation ◽  
The Past ◽  
Matrix Isolation Spectroscopy ◽  
The Matrix ◽  
Recent Developments ◽  
Quantum Chemical Computations ◽  
Insight Into

Within the past four decades, matrix isolation spectroscopy has emerged as the method of choice for obtaining direct structural information on benzynes and related dehydroaromatics. In combination with quantum chemical computations, detailed insight into the structure and reactivity of di-, tri-, and tetradehydrobenzenes has been obtained. This Review focuses on rather recent developments in aryne chemistry with a special emphasis on the matrix isolation of tridehydrobenzenes and related systems.

Crystal and electronic structure of the new ternary phosphide Ho5Pd19P12

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Olha Zhak ◽  
Oksana Karychort ◽  
Volodymyr Babizhetskyy ◽  
Chong Zheng
Keyword(s):  
Crystal Structure ◽  
Electronic Structure ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Structure Property ◽  
X Ray Diffraction ◽  
Structure Property Relationships ◽  
Metallic Bonding ◽  
Crystal And Electronic Structure ◽  
Insight Into

Abstract The title compound was prepared from the pure elements by sintering. The crystal structure was investigated by means of powder X-ray diffraction data. Ho5Pd19P12 exhibits the hexagonal Ho5Ni19P12-type structure with space group P 6 ‾ 2 m $P‾{6}2m$ , a = 13.1342(2), c = 3.9839(1) Å, R I = 0.060, R p = 0.080. The crystal structure can be described as a combination of two types of the structural units, [HoPd6P3] and [Ho3Pd10P6], respectively, mutually displaced by 1/2 along the crystallographic c axis. Quantum chemical calculations have been performed to analyze the electronic structure and provide deeper insight into the structure-property relationships. The results of the quantum chemical calculations indicate that the material features metallic bonding between Ho and Pd and covalent bonding between Pd and P.

Spectroscopy of Matrices and Thin Films with an Integrating Sphere

1989 ◽  
Vol 43 (2) ◽  
pp. 320-324 ◽  
Author(s):  
E. Berger ◽  
D. W. T. Griffith ◽  
G. Schuster ◽  
S. R. Wilson
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Experimental Approach ◽  
Matrix Isolation ◽  
Standard Theory ◽  
Integrating Sphere ◽  
Weak Absorption ◽  
Matrix Isolation Spectroscopy ◽  
Reflected Light ◽  
The Matrix

The paper describes a novel experimental approach to improving sensitivity to weak absorption in matrix isolation and thin film spectroscopy. The matrix or film is grown on the surface of an integrating sphere, in which the multiply reflected light correspondingly multipasses the sample film. The quantitative photometric behavior of the sphere is satisfactorily described by extending standard theory. Enhancement of absorption by a factor of at least 20 is possible and is demonstrated. The sphere has a number of useful advantages over other multipass techniques, particularly in matrix isolation spectroscopy.

Electronic structure and properties of alkoxymethylenemalonic acid derivatives

1979 ◽  
Vol 44 (5) ◽  
pp. 1423-1433 ◽  
Author(s):  
Dušan Ilavský ◽  
Jiří Krechl ◽  
Petr Trška ◽  
Josef Kuthan
Keyword(s):  
Electronic Structure ◽  
Quantum Chemical ◽  
Chemical Reactivity ◽  
Dipole Moments ◽  
Structure And Properties ◽  
Geometrical Isomers ◽  
H Nmr ◽  
Geometrical Isomerism ◽  
Pmr Spectra ◽  
Insight Into

Six compounds RO(H)C=C(X)CN with R = CH3 or C2H5 and X = CO2CH3, CO2C2H5 or CN are characterized by some spectral data (IR, UV, 1H NMR - solvent effect). The PMR spectra did not confirm the presence of two geometrical isomers. Employing the quantum chemical calculations of the substance with R = CH3 and X = CO2CH3 based on EHT, PPP, HMO and CNDO/2, the geometrical isomerism is discussed in relation to the experimental dipole moments. The HMO indices of chemical reactivity agree with our present synthetic insight into nucleophilic substitution of the derivatives under study.

scholarly journals Design of carborane molecular architectures with electronic structure computations: From endohedral and polyradical systems to multidimensional networks

2009 ◽  
Vol 81 (4) ◽  
pp. 719-729 ◽  
Author(s):  
Josep M. Oliva ◽  
Douglas J. Klein ◽  
Paul von Ragué Schleyer ◽  
Luis Serrano-Andrés
Keyword(s):  
Electronic Structure ◽  
Quantum Chemical ◽  
Triplet States ◽  
Triplet Energy ◽  
Self Assembling ◽  
Energy Gaps ◽  
Molecular Architectures ◽  
High Level ◽  
Quantum Chemical Computations ◽  
Structure Properties

The 12 cage-anchoring points of the very stable icosahedral ortho-, meta-, and para-carborane allow the design of multidimensional architectures provided new self-assembling routes are devised. We provide bases for constructing carborane molecular architectures through high-level quantum chemical computations. We consider ejection mechanisms for the inner atom/ion in endohedral carborane complexes, singlet-triplet energy gaps in carborane biradicals, as well as geometry reorganization in carborane neutral and dianionic triplet states. These features, explored in monomers, are starting points for the design of molecular architectures based on electronic structure properties of carborane assemblies.

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