The shortest chalcogen...halogen contacts in molecular crystals

2019 ◽  
Vol 75 (5) ◽  
pp. 865-869 ◽  
Author(s):  
Michał Kaźmierczak ◽  
Andrzej Katrusiak
Keyword(s):  
Interatomic Distance ◽  
Main Type ◽  
Van Der Waals ◽  
Molecular Crystals ◽  
Structural Models ◽  
Covalent Bond ◽  
Cambridge Structural Database ◽  
Molecular Arrangement ◽  
Structural Database ◽  
Van Der Waals Radii

The survey of the shortest contacts in structures deposited in the Cambridge Structural Database shows that chalcogen...halogen, halogen...halogen and chalcogen...chalcogen interactions can compete as cohesion forces in molecular crystals. The smallest parameter δ (defined as the interatomic distance minus the sum of relevant van der Waals radii) for Ch...X contacts between chalcogens (Ch: S, Se) and halogens (X: F, Cl, Br, I) is present only in 0.86% out of 30 766 deposited structures containing these atoms. Thus, in less than 1% of these structures can the Ch...X forces be considered as the main type of cohesion forces responsible for the molecular arrangement. Among the 263 structures with the shortest Ch...X contact, there are four crystals where no contacts shorter than the sums of van der Waals radii are present (so-called loose crystals). The smallest δ criterion has been used for distinguishing between the bonding (covalent bond) and non-bonding contacts and for validating the structural models of crystals.

The nature of the C–Br⋯Br–C intermolecular interactions found in molecular crystals: a general theoretical-database study

CrystEngComm ◽  
2015 ◽  
Vol 17 (17) ◽  
pp. 3354-3365 ◽  
Author(s):  
Marçal Capdevila-Cortada ◽  
Juan J. Novoa
Keyword(s):  
Intermolecular Interactions ◽  
Theoretical Calculations ◽  
Molecular Crystals ◽  
Cambridge Structural Database ◽  
Database Study ◽  
Structural Database

The properties of C–Br⋯Br–C interactions have been determined by doing MP2 theoretical calculations on model dimers and on dimers taken from the Cambridge Structural Database (presenting Br⋯Br distances within the 3.0 to 4.5 Å range).

Wechselwirkungen in Molekülkristallen, 168 [1,2]. σ-Donator/Akzeptor-Komplexe {HCl3···Xe⊖ }(X⊖ = Cl, Br⊖ , I⊖ ) von Triiodmethan in Tetraphenylphosphoniumhalogeniden / Interaction in Molecular Crystals, 168 [1, 2]. σ-Donor/Acceptor Complexes {HCl3 ···X⊖} (X⊖ = Cl⊖ , Br⊖ , I⊖ ) of Triiodomethane in Tetraphenylphosphonium Halides

2001 ◽  
Vol 56 (2) ◽  
pp. 152-163 ◽  
Author(s):  
Hans Bock ◽  
Sven Holl
Keyword(s):  
Low Temperature ◽  
Crystal Packing ◽  
Molecular Crystals ◽  
Cambridge Structural Database ◽  
Halide Anion ◽  
Structure Comparison ◽  
Halogen Compounds ◽  
Donor Acceptor ◽  
Structural Database ◽  
Halide Salts

AbstractThree donor/acceptor complexes between halide anion donors and the triiodomethane acceptor with tetraphenylphosphonium countercations, {(H5C6)4P⊕ X⊖ ··· I3CH)} (X⊖ = Cl⊖ , Br⊖, I⊖ ) could be crystallized and their structures determined at low temperature. Their crystal packing motifs are donor/acceptor layers of halide anion/triiodomethane patterns and phenyl/ phenyl interacting tetraphenylphosphonium cation chains. Structure comparison and discussion are based on literature-known analogous adducts with organoammonium salts as well as the phenyl/phenyl interactions in the numerous tetraphenylphosphonium salts registered in the Cambridge Structural Database. The results add novel facets to the selforganization phenomena observed on crystallization of halogen compounds and halide salts.

scholarly journals A survey of thermal expansion coefficients for organic molecular crystals in the Cambridge Structural Database

2021 ◽  
Vol 77 (3) ◽  
Author(s):  
Andrew D. Bond
Keyword(s):  
Thermal Expansion ◽  
Standard Deviation ◽  
Linear Relationship ◽  
Molecular Crystals ◽  
Cambridge Structural Database ◽  
Normal Distributions ◽  
Organic Molecular Crystals ◽  
Thermal Expansion Coefficients ◽  
Structural Database ◽  
Expansion Coefficients

Typical ranges of thermal expansion coefficients are established for organic molecular crystals in the Cambridge Structural Database. The CSD Python API is used to extract 6201 crystal structures determined close to room temperature and at least one lower temperature down to 90 K. The data set is dominated by structure families with only two temperature points and is subject to various sources of error, including incorrect temperature reporting and missing flags for variable-pressure studies. For structure families comprising four or more temperature points in the range 90–300 K, a linear relationship between unit-cell volume and temperature is shown to be a reasonable approximation. For a selected subset of 210 structures showing an optimal linear fit, the volumetric expansion coefficient at 298 K has mean 173 p.p.m. K−1 and standard deviation 47 p.p.m.  K−1. The full set of 6201 structures shows a similar distribution, which is fitted by a normal distribution with mean 161 p.p.m. K−1 and standard deviation 51 p.p.m. K−1, with excess population in the tails mainly comprising unreliable entries. The distribution of principal expansion coefficients, extracted under the assumption of a linear relationship between length and temperature, shows a positive skew and can be approximated by two half normal distributions centred on 33 p.p.m. K−1 with standard deviations 40 p.p.m. K−1 (lower side) and 56 p.p.m. K−1 (upper side). The distribution for the full structure set is comparable to that of the test subset, and the overall frequency of biaxial and uniaxial negative thermal expansion is estimated to be < 5% and ∼30%, respectively. A measure of the expansion anisotropy shows a positively skewed distribution, similar to the principal expansion coefficients themselves, and ranges based on suggested half normal distributions are shown to highlight literature cases of exceptional thermal expansion.

The structure of 1,2,4,4,6-pentaphenyl-1,4-dihydropyridine

1990 ◽  
Vol 55 (8) ◽  
pp. 2059-2065 ◽  
Author(s):  
Jaroslav Vojtěchovský ◽  
Jindřich Hašek ◽  
Jiří Ječný ◽  
Karel Huml
Keyword(s):  
Title Compound ◽  
Cambridge Structural Database ◽  
Boat Conformation ◽  
Planar Conformation ◽  
Structural Database ◽  
Independent Molecules ◽  
Dihydropyridine Ring

Title compound is triclinic, Mr = 461.60; P1, a = 9.158(1), b = 16.062(3), c = 19.472(3) Å, α = 110.69(1)°, β = 89.70(1)°, γ = 103.17(1)°, V = 2 600(1) Å3, Z = 4, Do = 1.15(3), Dc = 1.179(1) Mg m-3, λ(CuKα) = 1.5418 Å, μ = 0.509 mm-1, F(000) = 976 K, R = 0.040 for 8 059 unique observed reflections. Both symmetrically independent molecules show a different geometry of the 1,4-dihydropyridine ring: either the boat conformation with apexes C(sp3), N and boat angles 14.7(3)° and 10.3(2)° respectively, or the planar conformation. The conformation has been compared with similar dihydropyridines obtained from Cambridge Structural Database.

scholarly journals Targeted classification of metal–organic frameworks in the Cambridge structural database (CSD)

2020 ◽  
Vol 11 (32) ◽  
pp. 8373-8387 ◽  
Author(s):  
Peyman Z. Moghadam ◽  
Aurelia Li ◽  
Xiao-Wei Liu ◽  
Rocio Bueno-Perez ◽  
Shu-Dong Wang ◽  
...  
Keyword(s):  
Surface Chemistry ◽  
Specific Surface ◽  
Large Scale ◽  
Metal Cluster ◽  
Metal Organic Frameworks ◽  
Cambridge Structural Database ◽  
Metal Organic ◽  
Structural Database

Large-scale targeted exploration of metal–organic frameworks (MOFs) with characteristics such as specific surface chemistry or metal-cluster family has not been investigated so far.

Applications of the Cambridge Structural Database to molecular inorganic chemistry

2002 ◽  
Vol 58 (3) ◽  
pp. 398-406 ◽  
Author(s):  
A. Guy Orpen
Keyword(s):  
Inorganic Chemistry ◽  
Structural Data ◽  
Cambridge Structural Database ◽  
High Quality ◽  
Computational Data ◽  
Inorganic Complexes ◽  
Fundamental Research ◽  
Structural Database ◽  
Structure Correlation ◽  
Molecular Dimensions

Applications of the data in the Cambridge Structural Database (CSD) to knowledge acquisition and fundamental research in molecular inorganic chemistry are reviewed. Various classes of application are identified, including the derivation of typical molecular dimensions and their variability and transferability, the derivation and testing of theories of molecular structure and bonding, the identification of reaction paths and related conformational analyses based on the structure correlation hypothesis, and the identification of common and presumably energetically favourable intermolecular interactions. In many of these areas, the availability of plentiful structural data from the CSD is set against the emergence of high-quality computational data on the geometry and energy of inorganic complexes.

Sign in / Sign up

Export Citation Format

Share Document