An examination of the influence of crystal structure on molecular structure. The crystal and molecular structures of some diorganotinchloro-(N,N-dialkyldithiocarbamate)s, R2Sn(S2CNR′2)Cl, R = Me, tBu, Ph, Cy; R′2 = (Et)2, (Et, Cy) and (Cy)2: a comparison between solid state and theoretical structures

1999 ◽  
Vol 214 (2) ◽  
Author(s):  
E. R. T. Tiekink ◽  
V. J. Hall ◽  
M. A. Buntine
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Solid State ◽  
General Formula ◽  
Molecular Structures ◽  
Crystal And Molecular Structures

AbstractThe crystal and molecular structures of five compounds of the general formula R

Structural diversity in the mercury(II) bis(N,N-dialkyldithiocarbamate) compounds: an example of the importance of considering crystal structure when rationalising molecular structure

1999 ◽  
Vol 214 (9) ◽  
Author(s):  
M. J. Cox ◽  
E. R. T. Tiekink
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
General Formula ◽  
Structural Diversity ◽  
Molecular Structures ◽  
Crystal And Molecular Structures ◽  
Layer Structures

AbstractThe crystal and molecular structures of four compounds of the general formula Hg(SThus, when there are no steric restrictions precluding association in the lattice, Hg–S interactions are present that give rise to dimeric structures or 2-dimensional layer structures in the case when R = H.

Crystal and molecular structures of two polymorphs of 2,2-di(p-nitrophenyl)-1-picrylhydrazine dichloromethane, C18H11N7O10•CH2Cl2

1991 ◽  
Vol 69 (8) ◽  
pp. 1306-1314 ◽  
Author(s):  
Hong Wang ◽  
Richard J. Barton ◽  
Beverly E. Robertson ◽  
John A. Weil ◽  
Keith C. Brown
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Solvent Molecule ◽  
Molecular Structures ◽  
The Other ◽  
Dichloromethane Solution ◽  
Crystal Forms ◽  
Strong Resonance ◽  
Crystal And Molecular Structures ◽  
The Difference

Two polymorphic crystal forms (yellow and orange) of 2,2-di(p-nitrophenyl)-1-picrylhydrazine were crystallized from the same dichloromethane solution, and their crystal structures determined. The yellow form is triclinic, P1, a = 9.055(3), b = 10.396(4), c = 13.3187(3) Å, α = 89.83(2), β = 79.89(3), γ = 70.83(3)° at 228 K; R = 0.060, and Rw = 0.057 for 3511 reflections with I > 2σI. The orange form is monoclinic, P21/c, a = 8.999(3), b = 25.041(11), c = 12.207(5) Å, β = 121.66(2)° at 223 K; R = 0.053, and Rw = 0.058 for 3651 reflections with I > 2σI. The molecular structures in the two crystal forms are very similar. Both forms contain one solvent molecule per molecule of 2,2-di(p-nitrophenyl)-1-picrylhydrazine. In each, the two hydrazine nitrogen atoms have strong resonance interactions with the vicinal aromatic groups and both are sp2 hybridized. The molecular structure around the N—N linkage shows a staggered conformation. Thus the resonance interaction between the picryl group and the other two p-nitrophenyl groups is negligible. The difference in color between the two crystal forms is attributed to a difference in molecular packing. Key words: crystal structure, polymorphism, picrylhydrazine, conformation.

Synthesis and crystal structure analyses of tri-substituted guanidine-based copper(II) complexes

2021 ◽  
Vol 76 (3-4) ◽  
pp. 193-199
Author(s):  
Muhammad Said ◽  
Sadia Rehman ◽  
Muhammad Ikram ◽  
Hizbullah Khan ◽  
Carola Schulzke
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Molecular Structures ◽  
Hydroxyl Groups ◽  
Synthesis And Crystal Structure ◽  
Pyramidal Geometry ◽  
Tautomeric Forms ◽  
Square Planar ◽  
Nitrogen Donor ◽  
Square Pyramidal Geometry

Abstract Three guanidine-derived tri-substituted ligands viz. N-pivaloyl-N′,N″-bis-(2-methoxyphenyl)guanidine (L1), N-pivaloyl-N′-(2-methoxyphenyl)-N″-phenylguanidine (L2) and N-pivaloyl-N′-(2-methoxyphenyl)-N″-(2-tolyl)guanidine (L3) were reacted with Cu(II) acetate to produce the corresponding complexes. The significance of the substituent on N″ for the resulting molecular structures and their packing in the solid state has been studied with respect to the structural specifics of the corresponding Cu(II) complexes. The key characteristic of the guanidine-based metal complexation with Cu(II) is the formation of an essentially square planar core with an N2O2 donor set. As an exception, in the complex of L1, the substituent’s methoxy moiety also interacts with the Cu(II) center to generate a square-pyramidal geometry. The hydroxyl groups of the imidic acid tautomeric forms of L1–L3, in addition to N″, are also bonded to Cu(II) in all three complexes rather than the nitrogen donor of the guanidine motif.

Structural and spectroscopic studies of transition metal nitrite complexes. VIII. Crystal structures and spectra of three pentanuclear species with stoichiometry [Ni5(N-substituted ethane-1,2-diamine)4(OH)2(NO2)8]

1981 ◽  
Vol 34 (10) ◽  
pp. 2139 ◽  
Author(s):  
AJ Finney ◽  
MA Hitchman ◽  
CL Raston ◽  
GL Rowbottom ◽  
AH White
Keyword(s):  
Transition Metal ◽  
Crystal Structures ◽  
General Formula ◽  
Infrared Spectra ◽  
Spectroscopic Studies ◽  
Molecular Structures ◽  
Structural Variations ◽  
Crystal And Molecular Structures

The preparation of a series of novel compounds of general formula [Ni5L4(NO2)8(OH)2] formed by ethane-1,2-diamine or one of five N-substituted ethane-1,2-diamines (L) is described. The crystal and molecular structures of the ethane-1,2-diamine, N,N'-diethylethane-1,2-diamine and N,N-dimethylethane-1,2-diamine complexes are reported. Each compound contains a planar, pentameric arrangement of nickel(II) ions, linked by bridging hydroxide and nitrite ligands. The details of the nitrite bridges differ among the complexes, causing differences in their electronic and infrared spectra. The structural variations are probably caused by the differing steric requirements of the amine substituents.

Structural diversity in mercury(II) bis (O-alkyldithiocarbonate) compounds

1999 ◽  
Vol 214 (8) ◽  
Author(s):  
M. J. Cox ◽  
E. R. T. Tiekink
Keyword(s):  
General Formula ◽  
Structural Diversity ◽  
Molecular Structures ◽  
Crystal And Molecular Structures

AbstractThe crystal and molecular structures of four compounds of the general formula Hg(S

Experimental and computational structural study of two hindered aminoanthraquinones in crystals and solutions

2000 ◽  
Vol 215 (9) ◽  
Author(s):  
A.V. Yatsenko ◽  
K.A. Paseshnichenko ◽  
S.I. Popov
Keyword(s):  
Solid State ◽  
Single Crystal ◽  
Electronic Spectra ◽  
Molecular Structures ◽  
Amino Group ◽  
Single Crystal Diffraction ◽  
Molecular Conformations ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Visible Spectra

The crystal and molecular structures of 2-methyl-1-methylamino-anthraquinone (I) and 1-methylphenylamino-anthraquinone (II) were studied by the X-ray single-crystal diffraction and the visible spectra of crystalline specimens and their solutions were recorded. The molecule I is closely planar, whereas in the molecule II the amino group is 58° rotated out of the plane of the anthraquinone skeleton. In both structures the molecules pack in stacks. The comparison of experimental and calculated (on the DFT and AM1 levels) molecular structures, together with the comparison of experimental and INDO/S-calculated electronic spectra, give the evidence that molecular conformations (especially for II) change upon transfer from the solid state to solutions, and the π-delocalisation throughout the whole molecule enhances in the solid state.

Crystal and molecular structures of 4-aryl-1,4-dihydropyrimidines: Novel calcium channel antagonists

2003 ◽  
Vol 218 (1) ◽  
Author(s):  
K. Chandra Mohan ◽  
K. Ravikumar ◽  
M. M. Shetty ◽  
D. Velmurugan
Keyword(s):  
Solid State ◽  
Calcium Channel ◽  
Molecular Structures ◽  
Calcium Channel Antagonists ◽  
Crystal And Molecular Structures ◽  
Solid State Structures

AbstractThe solid-state structures of three calcium channel antagonists viz. 1,4-dihydro-6-methyl-5-N-methyl-carbamoyl-4-(3′,4′-dichlorophenyl)-2(3 H)-pyrimidinethione, C

Untersuchungen an Stickstoff-Brom-Verbindungen, IV / Studies on Nitrogen-Bromine Compounds, IV

1977 ◽  
Vol 32 (12) ◽  
pp. 1416-1420 ◽  
Author(s):  
Omar Jabay ◽  
Hans Pritzkow ◽  
Jochen Jander
Keyword(s):  
Crystal Structure ◽  
Nitrogen Atom ◽  
Structure Analysis ◽  
Electron Acceptors ◽  
Molecular Structures ◽  
Hydrogen Atoms ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Solid Nitrogen ◽  
Intermolecular Contacts

The crystal and molecular structures of N-bromobenzamide (NBB), N-bromosuccinimide (NBS), and N,N-dibromobenzenesulfonamide (NBBS) were determined by X-ray structure analysis. The nitrogen atoms in NBB and NBS have a trigonal planar coordination (sp2) and the N—Br distances lie in the same range (1.82 A, 1.84 A). The N—Br distance in NBBS, where the nitrogen atom is sp3-hybridized, is somewhat longer (1.88 A). In these structures the molecules are connected by O···H—N (NBB), O···Br—N (NBS) or N···Br—N (NBBS) intermolecular bonds forming endless chains; positivated hydrogen atoms or, in case that they are absent, positivated bromine atoms act as electron acceptors with oxygen or sp3- hybridized nitrogen atoms. These results suggest, that in solid nitrogen tribromide, the crystal structure of which cannot be determined, the nitrogen atoms will be sp3-hybridized and intermolecular contacts via N—Br···N will occur.

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