scholarly journals Regium Bonds between Silver(I) Pyrazolates Dinuclear Complexes and Lewis Bases (N2, OH2, NCH, SH2, NH3, PH3, CO and CNH)

Crystals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 137 ◽  
Author(s):  
Ibon Alkorta ◽  
Cristina Trujillo ◽  
Goar Sánchez-Sanz ◽  
José Elguero
Keyword(s):  
Theoretical Study ◽  
Cambridge Structural Database ◽  
Dinuclear Complexes ◽  
Chemical Shielding ◽  
Lewis Bases ◽  
Aromatic Character ◽  
Structural Database

A theoretical study and Cambridge Structural Database (CSD) search of dinuclear Ag(I) pyrazolates interactions with Lewis bases were carried out and the effect of the substituents and ligands on the structure and on the aromaticity were analyzed. A relationship between the intramolecular Ag–Ag distance and stability was found in the unsubstituted system, which indicates a destabilization at longer distances compensated by ligands upon complexation. It was also observed that the asymmetrical interaction with phosphines as ligands increases the Ag–Ag distance. This increase is dramatically higher when two simultaneous PH3 ligands are taken into account. The calculated 109Ag chemical shielding shows variation up to 1200 ppm due to the complexation. Calculations showed that six-membered rings possessed non-aromatic character while pyrazole rings do not change their aromatic character significantly upon complexation.

Aromaticity of benzene derivatives: an exploration of the Cambridge Structural Database

2018 ◽  
Vol 74 (2) ◽  
pp. 148-151 ◽  
Author(s):  
Irena Majerz ◽  
Teresa Dziembowska
Keyword(s):  
Solid State ◽  
Harmonic Oscillator ◽  
Cambridge Structural Database ◽  
Homa Index ◽  
Benzene Derivatives ◽  
Aromatic Character ◽  
Harmonic Oscillator Model ◽  
Benzene Rings ◽  
Structural Database ◽  
Hydroxy Groups

The harmonic oscillator model of aromaticity (HOMA) index, one of the most popular aromaticity indices for solid-state benzene rings in the Cambridge Structural Database (CSD), has been analyzed. The histograms of HOMA for benzene, for benzene derivatives with one formyl, nitro, amino or hydroxy group as well as the histograms for the derivatives with two formyl, nitro, amino or hydroxy groups inortho,metaandparapositions were investigated. The majority of the substituted benzene derivatives in the CSD are characterized by a high value of HOMA, indicating fully aromatic character; however, the distribution of the HOMA value from 1 to about 0 indicates decreasing aromaticity down to non-aromatic character. Among the benzene derivatives investigated, a significant decrease in aromaticity can be related to compounds with diamino and dinitro groups in themetaposition.

Halogen bonding versuschalcogen and pnicogen bonding: a combined Cambridge structural database and theoretical study

CrystEngComm ◽  
2013 ◽  
Vol 15 (16) ◽  
pp. 3137-3144 ◽  
Author(s):  
Antonio Bauzá ◽  
David Quiñonero ◽  
Pere M. Deyà ◽  
Antonio Frontera
Keyword(s):  
Theoretical Study ◽  
Halogen Bonding ◽  
Cambridge Structural Database ◽  
Structural Database

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.

Spacer conformation in biologically active molecules

2004 ◽  
Vol 76 (5) ◽  
pp. 959-964 ◽  
Author(s):  
J. Karolak-Wojciechowska ◽  
A. Fruzinski
Keyword(s):  
Statistical Data ◽  
Population Analysis ◽  
Cambridge Structural Database ◽  
Biologically Active ◽  
Aliphatic Chain ◽  
X Ray ◽  
Flexible Spacer ◽  
Conformational Preferences ◽  
Structural Database ◽  
The One

Based on our contemporary studies on the structures of biologically active molecules, we focus our attention on the aliphatic chain and its conformation. That flexible spacer definitely influenced the balanced position of all pharmacophoric points in molecules of biological ligands. The one atomic linker and two or three atomic spacers with one heteroatom X =O, S, CH2, NH have been taken into account. The conformational preferences clearly depend on the heteroatom X. In the discussion, we utilize our own X-ray data, computation chemistry methods, population analysis, and statistical data from the Cambridge Structural Database (CSD).

Five pseudopolymorphs of 6-amino-2-thiouracil: absence of N—H...S hydrogen bonds

2012 ◽  
Vol 69 (1) ◽  
pp. 93-100 ◽  
Author(s):  
Wilhelm Maximilian Hützler ◽  
Michael Bolte
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Cambridge Structural Database ◽  
Hydrogen Bonding Pattern ◽  
Crystallization Experiments ◽  
Structural Database ◽  
Thiouracil Derivatives

In order to study the preferred hydrogen-bonding pattern of 6-amino-2-thiouracil, C4H5N3OS, (I), crystallization experiments yielded five different pseudopolymorphs of (I), namely the dimethylformamide disolvate, C4H5N3OS·2C3H7NO, (Ia), the dimethylacetamide monosolvate, C4H5N3OS·C4H9NO, (Ib), the dimethylacetamide sesquisolvate, C4H5N3OS·1.5C4H9NO, (Ic), and two different 1-methylpyrrolidin-2-one sesquisolvates, C4H5N3OS·1.5C5H9NO, (Id) and (Ie). All structures containR21(6) N—H...O hydrogen-bond motifs. In the latter four structures, additionalR22(8) N—H...O hydrogen-bond motifs are present stabilizing homodimers of (I). No type of hydrogen bond other than N—H...O is observed. According to a search of the Cambridge Structural Database, most 2-thiouracil derivatives form homodimers stabilized by anR22(8) hydrogen-bonding pattern, with (i) only N—H...O, (ii) only N—H...S or (iii) alternating pairs of N—H...O and N—H...S hydrogen bonds.

scholarly journals What’s in an Atom? a Comparison of Carbon and Silicon-Centered Amidinium···carboxylate Frameworks

2020 ◽  
Author(s):  
Stephanie Boer ◽  
Li-Juan Yu ◽  
Tobias Genet ◽  
Kaycee Low ◽  
Duncan Cullen ◽  
...  
Keyword(s):  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Building Blocks ◽  
Cambridge Structural Database ◽  
Bond Angles ◽  
Framework Materials ◽  
Carboxylate Anions ◽  
Tetrahedral Bond ◽  
Structural Database ◽  
Apparent Similarity

<div><div><div><p>Despite their apparent similarity, framework materials based on tetraphenylmethane and tetraphenylsilane building blocks often have quite different structures and topologies. Herein, we describe a new silicon tetraamidinium compound and use it to prepare crystalline hydrogen bonded frameworks with carboxylate anions in water. The silicon-containing frameworks are compared with those prepared from the analogous carbon tetraamidinium: when biphenyldicarboxylate or tetrakis(4-carboxyphenyl)methane anions were used similar channel-containing networks are observed for both the silicon and carbon tetraamidinium. When terephthalate or bicarbonate anions were used, different products form. Insights into possible reasons for the different products are provided by a survey of the Cambridge Structural Database and quantum chemical calculations, both of which indicate that, contrary to expectations, tetraphenylsilane derivatives have less geometrical flexibility than tetraphenylmethane derivatives, i.e. they are less able to distort away from ideal tetrahedral bond angles.</p></div></div></div>

Sign in / Sign up

Export Citation Format

Share Document