The Molecular Structure of 1,3,5,7- Tetra(tert-butyl)-2,4,6,8-tetra(chloro)- borazocine [1]

2009 ◽  
Vol 64 (9) ◽  
pp. 1090-1092 ◽  
Author(s):  
Heinrich Nöth
Keyword(s):  
Molecular Structure ◽  
Standard Deviation ◽  
Unit Cell ◽  
Monoclinic System ◽  
Space Group ◽  
Bond Angles ◽  
Bond Lengths ◽  
Twofold Axis ◽  
Crystallographic Symmetry ◽  
Independent Molecules

The borazocine (ClB=NCMe3)4 crystallizes in the monoclinic system, space group C2/c with Z = 6, i. e. there are two independent molecules in the unit cell. The first molecule has no crystallographic symmetry, while the second molecule is characterized by a twofold axis which generates the (ClB= NCMe3)4 molecule from the fragment (ClB=NCMe3)2. The molecules are tub-shaped showing alternating longer and shorter B-N bonds. Compared with the borazocine (N3B= NCM3)4 the BN bonds of (ClB=NCMe3)4 are on average shorter than those of the azide derivative. Although B-N bond lengths and N-B-N and B-N-B bond angles in both molecules of (ClB=NCMe3)4 are identical within the limits of the standard deviation, the opposite B2N2 planes differ significantly for the two independent molecules.

Crystal and molecular structure of fenspiride, C15H20N2O2

2020 ◽  
Vol 35 (2) ◽  
pp. 144-146
Author(s):  
Silvina Pagola
Keyword(s):  
Molecular Structure ◽  
General Position ◽  
Crystal And Molecular Structure ◽  
Unit Cell ◽  
Unit Cell Parameters ◽  
Monoclinic System ◽  
Inflammatory Drug ◽  
Space Group ◽  
Cell Parameters ◽  
Independent Molecules

The crystal and molecular structure of fenspiride, a bronchodilator and anti-inflammatory drug, are reported. Fenspiride crystallizes in the monoclinic system, with two crystallographically independent molecules in the general position of the space group P21/n (No. 14) and Z = 8. Rietveld refined unit cell parameters are a = 11.52013(8) Å, b = 5.614091(31) Å, c = 44.1567(4) Å, α = 90°, β = 93.0885(6)°, γ = 90°, and V = 2851.69(4) Å3.

Crystal and molecular structure of the nickel(II) chelate of salicylidenethiosemicarbazone ammine - C8H7N3OSNi.NH3

1981 ◽  
Vol 46 (4) ◽  
pp. 975-981 ◽  
Author(s):  
Eduard Gyepes ◽  
František Pavelčík ◽  
Anton Beňo
Keyword(s):  
Molecular Structure ◽  
Crystal And Molecular Structure ◽  
Specific Weight ◽  
Unit Cell ◽  
Lattice Parameters ◽  
Monoclinic System ◽  
Space Group ◽  
Symmetry Space ◽  
Symmetry Space Group

The nickel(II) chelate of salicylidenethiosemicarbazone ammine-C8H7N3OSNi.NH3 crystallizes in a monoclinic system. The lattice parameters are: a = 6.857(2), b = 9.763(2), c = 15.340(4) .10-10 m, β = 90.34(2)° and the volume of the unit cell V = 1027(1) . 10-30 m3; the specific weight was measured as dm = 1.76 Mg m-3 and calculated as dc = 1.74 Mg m-3. The number of formula units in the unit cell, Z = 4, and the symmetry space group is P21/c.

Kristall- und Molekülstruktur des dimeren 1,2-Dioxyphenylen-siliciumdichlorids / Crystal and Molecular Structure of the Dimeric 1,2-Dioxyphenylene Silicondichloride

1989 ◽  
Vol 44 (12) ◽  
pp. 1550-1554
Author(s):  
Wolfgang Hönle ◽  
Urszula Dettlaff-Weglikowska ◽  
Leonhard Walz ◽  
Hans Georg von Schnering
Keyword(s):  
Molecular Structure ◽  
Viscous Liquid ◽  
Crystal And Molecular Structure ◽  
Chlorine Atoms ◽  
Space Group ◽  
Bond Angles ◽  
Bond Lengths ◽  
The Mean ◽  
Related Compounds

1,2-Dioxyphenylene silicondichloride is formed as a dimer from SiCl4 and catechol C6H4(OH)2 as the first reaction product. The compound melts at 413 K, yielding a viscous liquid which recrystallizes very slowly presumable under the formation of the monomer. 1,2-Dioxyphenylene silicondichloride crystallizes as a dimer in the space group P21/a (No. 14) with a = 1308.5(8) pm, b = 735.8(5) pm, c = 889.6(5) pm, β = 110.02(5)°, Z = 4 formula units. Silicon is tetrahedrally coordinated by two oxygen and two chlorine atoms with the mean bond lengths d̄(Si—O) = 160.7 pm and d̄(Si—Cl) = 200.7 pm. The bond angles at the Si atom range from 104.4 to 112.6° (endocyclic O—Si—O = 110.3°) and the bond angles ∢ (Si—O—C) are 131.4 and 135.9°, respectively. The results are discussed together with data of related compounds.

The Structure of the Tetraphenyldithioimidodiphosphinate Ion

1987 ◽  
Vol 42 (12) ◽  
pp. 1507-1509 ◽  
Author(s):  
Raymundo Cea-Olivares ◽  
Heinrich Nöth
Keyword(s):  
Bond Length ◽  
Unit Cell ◽  
Neutral Molecule ◽  
Monoclinic System ◽  
Space Group ◽  
Bond Angles

AbstractThe potassium 18-crown-6 ether salt of the title anion has been prepared. It crystallizes in the monoclinic system, space group C2/c, with four molecules in the unit cell. The anion possesses a crystallographically imposed C2 symmetry. The PN bond length of the anion is shorter and the PS bond longer than in the neutral molecule [Ph2P(S)]2NH , while the PNP bond angles are essentially the same.

The crystal and molecular structure of 3-N-pyridylsydnone

1985 ◽  
Vol 50 (8) ◽  
pp. 1764-1773 ◽  
Author(s):  
Jindřich Hašek ◽  
Paul T. Beurskens ◽  
Jiří Obrda ◽  
Stanislav Nešpůrek ◽  
Hendrik Schenk ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Title Compound ◽  
Crystal And Molecular Structure ◽  
Pyridyl Ring ◽  
Independent Molecule ◽  
Photochromic Properties ◽  
Monoclinic System ◽  
Calculated Density ◽  
Space Group ◽  
Independent Molecules

The title compound studied for its photochromic properties crystallizes in the monoclinic system, the space group P2/c, a = 734.3(6), b = 933.3(8), c = 2 334(2) pm, β = 117.71(5)°, V = 1.416(2) nm3, Z = 8, measured and calculated density Dm = 1.51, Dx = 1.53 Mg m-3, λ(CuKα) = 154.178 pm, μ = 1.0 mm-1, F(000) = 672, Mr= 163.14, T = 296 K. Final R = 0.084 for 1 511 significant (I > 1.96σI) reflections. The molecules are roughly parallel with the (100) plane and are stacked so that the sydnone ring of the first independent molecule partly overlaps the pyridyl ring of the second independent molecule. This results in the infinite column of partly overlaping pyridyl and sydnone rings in distances 344(4) and 335(4) pm, parallel with the a axis. Symmetrically independent molecules simulate pseudo 21 axis.

Contributions to the Chemistry of Boron, LXXXII. The Crystal and Molecular Structure of B,B′ -bis(1,3-dimethyl-1,3,2-diazaborolidin-2-yl)

1976 ◽  
Vol 31 (11) ◽  
pp. 1441-1446 ◽  
Author(s):  
H. Fusstetter ◽  
J. C. Huffman ◽  
H. Nöth ◽  
R. Schaeffer
Keyword(s):  
Molecular Structure ◽  
Title Compound ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Unit Cell ◽  
Full Matrix ◽  
Space Group ◽  
Independent Molecules

The title compound 2 crystallizes monoclinic, and the space group was determined to be C 2/c. The unit cell contains 16 molecules grouped in two sets of crystallographic independent molecules. The structure was solved by direct methods. Full matrix refinement led to R = 0.09. The molecules have C2 symmetry. The compound is composed of two five membered diazaborolidine rings joined by a boron-boron bond. The two nearly planar rings are twisted to one another by 61.6° and 56.8° respectively

The crystal and molecular structure of quaterrylene

1960 ◽  
Vol 257 (1291) ◽  
pp. 477-490 ◽  
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Crystal And Molecular Structure ◽  
Current Theory ◽  
Mean Value ◽  
Unit Cell ◽  
Two Dimensional ◽  
Monoclinic System ◽  
Space Group ◽  
The Mean

Quaterrylene (III) is isotypic with perylene (I); it crystallizes in the monoclinic system with a = 11·25, b = 10·66, c = 19·31 Å, β = 100·6°, and with four molecules per unit cell and the space group P 2 1 / a . The crystal structure has been determined by two-dimensional methods. In the b -axial projection a majority of the carbon atoms are resolved, and, since the molecule lies with its greatest length almost exactly perpendicular to this axis, the lengths of the peri -bonds connecting the naphthalenic residues have been determined with moderate accuracy. The mean value is assessed at 1·53 ± 0·01 Å, which is significantly larger than current theory predicts. Possible reasons for this difference are discussed.

Crystal Structure of Tetrabutylammonium Carbonyltribromoplatinate(II) [(C4H9)4N][PtBr3(CO)]

2002 ◽  
Vol 57 (6) ◽  
pp. 610-614 ◽  
Author(s):  
Michael Berkei ◽  
Jamie F. Bickley ◽  
Brian T. Heaton
Keyword(s):  
Crystal Structure ◽  
Bond Length ◽  
Unit Cell ◽  
Monoclinic System ◽  
Space Group ◽  
Bond Lengths

AbstractTetrabutylammonium carbonyltribromoplatinate(II) [(C4H9)4N][PtBr3(CO)] crystallises in the monoclinic system in the space group P21/n with a = 1487.84(13), b = 897.41(8), c = 1849.6(2) pm, β = 106.558(2)° and four formula units per unit cell. The [PtBr3 (CO)]- anion is symmetrical (C2v) and almost planar with Pt-Br bond lengths of 242.40(12) pm (trans to CO), 243.25(10) pm and 242.99(9) pm (trans to Br), and a Pt-C bond length of 185.6(11) pm.

Contributions to the Chemistry of Boron, LXXV The Crystal and Molecular Structure of a Tetraazadiborine: 3,6-Bis(dimethylamino)-1,2,4,5-tetramethyl-1,2,4,5,3,6-tetraazadiborine

1976 ◽  
Vol 31 (3) ◽  
pp. 289-293 ◽  
Author(s):  
J. C. Huffman ◽  
H. Fusstetter ◽  
H. Nöth
Keyword(s):  
Molecular Structure ◽  
Title Compound ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Membered Ring ◽  
Unit Cell ◽  
Hydrogen Atoms ◽  
Monoclinic System ◽  
Full Matrix ◽  
Bond Lengths

The title compound crystallizes in the monoclinic system with dimensions of the unit cell a = 14.09(2), b = 8.60(1), c = 11.34(1) Å and β = 101.7°. The space group was determined to be A 2/a with four molecules in the unit cell. The structure was solved by direct methods, and all hydrogen atoms were located. Full matrix refinement led to R = 0.059. The B2N4 six membered ring is nonplanar as expected for an 8π electron heterocycle. The molecule possesses C2 symmetry but the ring itself is near the D2 symmetry as derived from earlier CNDO/S-calculations. The BN bond lengths are 1.43 A, the NN distances 1.43 Å and the average CN distances 1.44 A. The boron atoms and four of the six nitrogen atoms are trigonal-planarly coordinated while the remaining two N-atoms (N1,N2) deviate little, but significantly, from sp2 hybridisation. The structure of the molecule can be interpreted as the best compromise between ΒΝ-π-bonding, nonbonding repulsion between adjacent CH3 groups, and the interaction between neighbouring ‘free pairs of electrons’ of the ring N-N-units.

Die Struktur des 2.3.4.6.7.8-Hexamethyl-2.3.4.6.7.8-hexaphosphabicyclo- [3.3.0] octans (PMe)6C2H2 / The Structure of 2,3,4,6,7,8-Hexamethyl-2,3,4,6,7,8-hexaphosphabicyclo[3,3,0]octane (PMe)6C2H2

1978 ◽  
Vol 33 (7) ◽  
pp. 698-701 ◽  
Author(s):  
Hans-Georg von Schnering ◽  
Wolfgang May
Keyword(s):  
Chair Conformation ◽  
Molecular Packing ◽  
Unit Cell ◽  
Methyl Groups ◽  
Trans Conformation ◽  
Space Group ◽  
Bond Lengths ◽  
Bicyclic System ◽  
The Mean ◽  
Independent Molecules

Abstract One of the diastereomeres of 2,3,4,6,7,8-hexamethyl-2,3,4,6,7,8-hexaphosphabicyclo-[3,3,0]octane (PMe)6C2H2 crystallizes in the space group P21/n with four molecules per unit cell. Two independent molecules are nearly identical in shape but differ by inter-molecular packing. The five-membered rings have a skew chair conformation with all exocyclic methyl groups in axial positions leading to a staggered all-trans conformation of the bicyclic system. The mean bond lengths are P-P = 220.9 pm, P-C = 185.9 pm and C-C = 151.9 pm.

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