Benchmarking dispersion-corrected DFT methods for the evaluation of materials with anisotropic properties: structural, electronic, dielectric, optical and vibrational analysis of calcite (CaCO3, space group R-3c)

2021 ◽  
Author(s):  
Gianfranco Ulian ◽  
Daniele Moro ◽  
Giovanni Valdre
Keyword(s):  
Physical Properties ◽  
Solid Phase ◽  
Vibrational Analysis ◽  
Simulation Methods ◽  
Dft Methods ◽  
Theoretical Simulation ◽  
Space Group ◽  
Anisotropic Properties

Calcite (CaCO3, space group R-3c) is a solid phase whose well-known highly anisotropic physical properties can be exploited to compare and calibrate various theoretical simulation methods. In this work, to...

scholarly journals Crystal-to-Crystal Transformation from K2[Co(C2O4)2(H2O)2]·4H2O to K2[Co(μ-C2O4)(C2O4)]

2021 ◽  
Vol 7 (6) ◽  
pp. 77
Author(s):  
Bin Zhang ◽  
Yan Zhang ◽  
Guangcai Chang ◽  
Zheming Wang ◽  
Daoben Zhu
Keyword(s):  
Hydrogen Bond ◽  
Physical Properties ◽  
Crystal Structures ◽  
Molecular Crystal ◽  
Trigonal Prism ◽  
Space Group ◽  
Cell Parameters ◽  
Oxalate Anion ◽  
Crystal Transformation ◽  
Antiferromagnetic Ordering

Crystal-to-crystal transformation is a path to obtain crystals with different crystal structures and physical properties. K2[Co(C2O4)2(H2O)2]·4H2O (1) is obtained from K2C2O4·2H2O, CoCl2·6H2O in H2O with a yield of 60%. It is crystallized in the triclinic with space group P1 and cell parameters: a = 7.684(1) Å, b = 9.011(1) Å, c = 10.874(1) Å, α = 72.151(2)°, β = 70.278(2)°, γ = 80.430(2)°, V = 670.0(1) Å3, Z = 2 at 100 K. 1 is composed of K+, mononuclear anion [Co(C2O4)2(H2O)22−] and H2O. Co2+ is coordinated by two bidentated oxalate anion and two H2O in an octahedron environment. There is a hydrogen bond between mononuclear anion [Co(C2O4)2(H2O)22−] and H2O. K2[Co(μ-C2O4)(C2O4)] (2) is obtained from 1 by dehydration. The cell parameters of 2 are a = 8.460(5) Å, b = 6.906 (4) Å, c = 14.657(8) Å, β = 93.11(1)°, V = 855.0(8) Å3 at 100 K, with space group in P2/c. It is composed of K+ and zigzag [Co(μ-C2O4)(C2O42−]n chain. Co2+ is coordinated by two bisbendentate oxalate and one bidentated oxalate anion in trigonal-prism. 1 is an antiferromagnetic molecular crystal. The antiferromagnetic ordering at 8.2 K is observed in 2.

scholarly journals 4-METHYL HYPPURIC ACID: A CASE OF POLYMORPHISM AND SOLVATOMORPHISM

2019 ◽  
Vol 16 (32) ◽  
pp. 812-819
Author(s):  
G. DELGADO ◽  
M. GUILLEN ◽  
A. J. MORA
Keyword(s):  
Pharmaceutical Industry ◽  
Physical Properties ◽  
Crystal Packing ◽  
Solid Material ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Space Group ◽  
Pharmaceutical Ingredients ◽  
Orthorhombic Cell

Polymorphism is known as the ability of a solid material to exist in more than one form or crystal structure, with important applications in the preparation of active pharmaceutical ingredients. Characterization of different polymorphs of the specific metabolite of 4-xylene can contribute to the chemical and pharmaceutical industry. Polymorphism is of particular importance in industrial processes, where different physical properties of polymorphic forms can substantially alter the viability and quality of a manufactured product. This is particularly so for the design and production of drugs in the pharmaceutical industry, as varying physical properties between different polymorphs can affect shelf life and durability, solubility, as well as bioavailability and manufacturing of the drug. The crystallization, spectroscopic and X-ray diffraction characterization of two polymorph and one solvatomorph of 4-methylhippuric acid are presented. These compounds crystallizes in different crystalline systems. Polymorph I (4mH-I) crystalize in an orthorhombic cell with space group P212121. Polymorph II (4mHII) crystallizes in a monoclinic space group P21/c. Solvatomorph (4mH-S) crystallizes in a triclinic P-1 cell. All polymorphs crystallize in neutral form. The crystal packing of the three compounds are governed by hydrogen bonds intermolecular interactions of the type N--H···O and O--H···O forming tridimensional networks.

Fluoride und Fluorosäuren, VIII [1]. Über eine fehlgeordnete feste Phase des SF4 sowie die Kristallstrukturen von Produkten seiner unbeabsichtigten Hydrolyse in Glasapparaturen, SiF4 (Neubestimmung) und SOF2 / Fluorides and Fluoro Acids, VIII [1]. On a Disordered Solid Phase of SF4 and the Crystal Structures of Products of its Unintentional Hydrolysis in Glass Apparatus, SiF4 (Redetermination) and SOF2

1984 ◽  
Vol 39 (10) ◽  
pp. 1295-1299 ◽  
Author(s):  
Dietrich Mootz ◽  
Lutz Korte
Keyword(s):  
Solid Phase ◽  
Zone Melting ◽  
Close Packing ◽  
Monoclinic Space Group ◽  
Space Group ◽  
Pyramidal Geometry ◽  
Vacuum Line ◽  
Melting Separation ◽  
Hydrolysis Of ◽  
Isolated Molecules

A structural investigation on single crystals of SF4 yielded the cubic space group Fm3m with a = 676.1(5) pm and Z = 4 and from this cubic close packing and at least sixfold disorder of isolated molecules. In one of the experiments of manipulating SF4 unintentional hydrolysis of the compound in a Duran-glass vacuum line occurred. The products SiF4 and SOF2 could be characterized by structure analysis after a miniature zone-melting separation and crystal growth in one and the same thin-walled capillary. The results for SiF4 [14̄3m, a = 547.6(1) pm, Z = 2 at -117 °C] confirm earlier work with a higher numerical accuracy. SOF2 crystallizes in the monoclinic space group P21/c with a = 524.7(1), b = 704.9(2), c = 1449.3(4) pm, β = 97.20(2)° at - 137 °C and Z = 8. Isolated molecules of pyramidal geometry are arranged in strongly folded layers with intermolecular S···O contacts.

scholarly journals DEVELOPMENT OF MOLECULAR IMPRINTED POLYMER SOLID PHASE EXTRACTION (MISPE) FOR SEPARATION NITROFURANTOIN RESIDUE IN CHICKEN EGGS

2017 ◽  
Vol 10 (6) ◽  
pp. 108
Author(s):  
Sophi Damayanti ◽  
Untung Gunawan ◽  
Slamet Ibrahim
Keyword(s):  
Solid Phase Extraction ◽  
Analytical Methods ◽  
Density Functional ◽  
Solid Phase ◽  
Basis Set ◽  
Phase Extraction ◽  
Molecular Imprinted Polymer ◽  
Imprinted Polymer ◽  
Dft Methods ◽  
The Matrix

Background: The use of nitrofurantoin and other nitrofuran antibiotics in food which produced from animals is prohibited by European Union because of potentially carcinogenic and mutagenic. Various methods for analysis of residues of nitrofurantoin has been developed, but because of the interference of the matrix, it is necessary to separate the matrix therefore, the matrix effect will not interfere the analysis. Nowadays, molecular imprinted polymer (MIP) is a well-developed tool in the analytical field, mainly for separating substances in relatively complex matrices.Objective: The purpose of this study is to obtain MISPE that is selective for the separation of nitrofurantoin residues in chicken eggs.Methods: Analytical methods development of nitrofurantoin were optimization of HPLC system and validation of analytical methods performed to obtain the suitable system for nitrofurantoin detection. In silico study used for MIP design by observing the difference Gibbs free energy using Gaussview 5.08 software with Density Functional Theory (DFT) methods using 6-311G as basis set. MIP synthesis was done using bulk method use nitrofurantoin as template, acrylamide as functional monomer, ethyleneglycoldimethacrylate (EGDMA) as crosslinker, and azobisisobutyronitrile (AIBN) as an initiator reaction inside dimethylformamide (DMF) as solvent. Non imprinted polymer (NIP) was synthesized as comparison. MIP and NIP which has been synthesized was inserted into SPE cartridge and characterized using Infrared spectroscopy and HPLC.Result: MISPE that has been synthesized was characterized and compared to non-imprinted polymer solid phase extraction (NISPE) and marketed Solid Phase Extraction (SPE) C18. Sensitivity of MIP, NIP, and SPE C-18 to nitrofurantoin was 84.54 %, 37.73 %, and 33.95 % respectively, based on recovery of nitrofurantoin.Conclusion: Based on the result it was obtained MISPE has high selectivity toward nitrofurantoin compared to NISPE and either marketed SPE.  

The crystal structure and vibrational spectra of cis-dichlorobis(cyclopropylamine)-platinum(II), PtCl2(C3H5NH2)2

1981 ◽  
Vol 59 (18) ◽  
pp. 2737-2745 ◽  
Author(s):  
Helen Elaine Howard-Lock ◽  
Colin James Lyne Lock ◽  
Graham Turner ◽  
Maruta Zvagulis
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Vibrational Spectra ◽  
Vibrational Analysis ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths ◽  
Deuterated Analogue

Crystals of cis-dichlorobis(cyclopropylamine)platinum(II), PtCl2(C3H5NH2)2, are monoclinic, a = 12.770(5), b = 5.838(2), c = 15.113(6) Å, β = 104.46(3)°, Z = 4, space group P21/c. The structure was solved by Patterson and Fourier syntheses and was refined by full-matrix least-squares to R = 0.057, Rw = 0.055 for 1577 reflections with I > 3σ(I). Bond lengths and angles are normal. A vibrational analysis of the compound and its d2-deuterated analogue was performed.

Isomers of 1,4,8,11-Tetraazacyclotetradecane-6,13-dicarboxylate Characterized as Cobalt(III) Complexes

2003 ◽  
Vol 56 (7) ◽  
pp. 679 ◽  
Author(s):  
Paul V. Bernhardt ◽  
Trevor W. Hambley ◽  
Geoffrey A. Lawrance ◽  
Marcel Maeder ◽  
Eric N. Wilkes
Keyword(s):  
Physical Properties ◽  
Octahedral Geometry ◽  
Trans Isomers ◽  
Space Group ◽  
Cell Parameters ◽  
Limited Distortion ◽  
Chelate Rings

The major trans (1) and minor cis (2) isomers of 1,4,8,11-tetraazacyclotetradecane-6,13-dicarboxylate have been characterized as the complexes [Co(1)](ClO4) and [Co(H2)(OH2)]Cl(ClO4)·H2O. The former crystallized in the C2/c space group and the latter in the P21/c space group, with cell parameters a 16.258(7), b 9.050(3), c 15.413(6) Å, β133.29(3)°, and a 9.694(4), b 16.135(1), c 12.973(5) Å, β 93.00(2)°, respectively. Their characterization completes identification of the respective trans and cis isomers for the series of c-pendant macrocycles also including 1,4,8,11-tetraazacyclotetradecane-6-amine-13-carboxylate ((3), (4)) and 1,4,8,11-tetraazacyclotetradecane-6,13-diamine ((5), (6)). The complexes show limited distortion from octahedral geometry with the strain in the presence of the coordinated c-pendant carboxylate significantly reduced compared with that for the c-pendant amine in analogues, a consequence mainly of six-membered as opposed to five-membered chelate rings involving the pendant donor. A comparison of the physical properties for the trans isomers of the octahedral complexes of (1), (3), and (5), which reflect progressively increasing strain, is presented.

Structural studies of organoboron compounds. XXXIII. 4,4-Dimethyl-2,2-diphenyl-1,3-dioxa-4-azonia-2-boratacyclohexaneand 3,3-dimethyl-2-phenoxy-2-phenyl-1-oxa-3-azonia-2-boratacyclopentane

1989 ◽  
Vol 67 (5) ◽  
pp. 933-940 ◽  
Author(s):  
Eckardt Ebeling ◽  
Wolfgang Kliegel ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Physical Properties ◽  
Crystal Structures ◽  
Direct Methods ◽  
Molecular Structures ◽  
Structural Studies ◽  
Boron Compounds ◽  
Organoboron Compounds ◽  
Thermally Induced ◽  
Full Matrix ◽  
Space Group

Details of the syntheses, physical properties, and crystal structures of the title compounds are reported. Crystals of 4,4-dimethyl-2,2-diphenyl-1,3-dioxa-4-azonia-2-boratacyclohexane, 3, are monoclinic, a = 6.512(1), b = 15.765(2), c = 14.342(4) Å, β = 93.170(7)°, Z = 4, space group Pn, and those of 3,3-dimethyl-2-phenoxy-2-phenyl-1-oxa-3-azonia-2-boratacyclopentane, 4, are orthorhombic, a = 13.5829(8), b = 16.940(1), c = 6.3181(4) Å, Z = 4, space group P21212. Both structures were solved by direct methods and were refined by full-matrix least-squares procedures to R = 0.034 and 0.034 for 1974 and 1478 reflections with I ≥ 3σ(I), respectively. The molecular structures are discussed in terms of the thermally-induced 1,2-migration of B-substituents by which 3 is converted to 4. Keywords: crystal structures, boron compounds, organoboron compounds.

Synthesis and crystal and molecular structure of ethanolaminogallium dimethyl, H2NCH2CH2O•GaMe2

1979 ◽  
Vol 57 (5) ◽  
pp. 586-590 ◽  
Author(s):  
Kenneth S. Chong ◽  
Steven J. Rettig ◽  
Alan Storr ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Hydrogen Bonds ◽  
Physical Properties ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Space Group ◽  
Bond Lengths ◽  
R Value

Details of the synthesis and physical properties of H2NCH2CH2O•GaMe2 are given. The compound crystallizes in the tetragonal space group P43, a = 12.2771(2), c = 9.7345(4) Å, Z = 8. The structure was solved by Patterson and Fourier syntheses and was refined by fullmatrix least-squares procedures to a final R value of 0.028 and Rw of 0.036 for 1378 reflections with I ≥ 3σ(I). The structure consists of monomeric molecules containing tetrahedrallycoordinated gallium atoms. Molecules are linked by an extensive network of N—H … O hydrogen bonds. Bond lengths (corrected for libration) are: Ga—O, 1.916(5) and 1.917(4), Ga—N, 2.056(6) and 2.072(6), and Ga—C, 1.962–1.974(8–9) Å.

Structural studies of organoboron compounds. XXXII. 5,5-Difluoro-2,2-pentamethylene-1,4,6-trioxa-3a-azonia-5-borata-1,2,3,4,5,6-hexahydrobenzo[h]azulene and 2,2-pentamethylene-5,5-diphenyl-1,4,6-trioxa-3a-azonia-5-borata-1,2,3,4,5,6-hexahydrobenzo[h]azulene

1988 ◽  
Vol 66 (10) ◽  
pp. 2621-2630 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Mahmood Tajerbashi ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Solid State ◽  
Physical Properties ◽  
Least Squares ◽  
Crystal Structures ◽  
Direct Methods ◽  
Structural Studies ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths ◽  
Conformational Isomers

Details of the syntheses, physical properties, and crystal structures of the title compounds are reported. Crystals of 5,5-difluoro-2,2-pentamethylene-1,4,6-trioxa-3a-azonia-5-borata-1,2,3,4,5,6-hexahydrobenzo[h]azulene are triclinic, a = 6.1576(3), b = 11.2651(3), c = 10.8118(3) Å, α = 109.747(3), β = 105.807(4), γ = 92.976(4)°, Z = 2, space group [Formula: see text], and those of 2,2-pentamethylene-5,5-diphenyl-1,4,6-trioxa-3a-azonia-5-borata-1,2,3,4,5,6-hexahydrobenzo[h]azulene are monoclinic, a = 9.8549(6), b = 10.9242(6), c = 41.263(2) Å, β = 92.717(6)°, Z = 8, space group P21/n. Both structures were solved by direct methods and were refined by full-matrix least-squares procedures to R = 0.045 and 0.042 for 2344 and 4248 reflections with I ≥ 3σ(I), respectively. The molecules were both found to possess a seven-membered chelate structure, the O,O-chelatїng ligand being strongly bound to the X2B moiety. Two conformational isomers of the X = Ph compound were found in the solid state. The 2-oxazoline N-oxide moieties present in both compounds are the first to be structurally characterized. Important mean libration-corrected bond lengths are: O—B = 1.491 and F—B = 1.387 Å for X = F; O—B = 1.511 and C—B = 1.620 Å for X = Ph.

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