Crystal and molecular structure of hexadecamethylcyclooctaphosphazene, (NPMe2)8

1977 ◽  
Vol 55 (13) ◽  
pp. 2530-2533 ◽  
Author(s):  
Richard T. Oakley ◽  
Norman L. Paddock ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Membered Ring ◽  
Weighted Mean ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths ◽  
The Mean

Crystals of hexadecamethylcyclooctaphosphazene are tetragonal, a = 13.637(1), c = 8.215(1) Å, Z = 2, space group P4/n. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to a final R of 0.033 and Rw of 0.032 for 1306 reflections with I ≥ 4σ(I) The molecule has crystallographic fourfold (C4) symmetry with weighted mean bond lengths P—N, 1.590(13), P—C, 1.811(2), and C—H, 0.95(2) Å (those not involving hydrogen have been corrected for libration, rms deviations from the mean are given in parentheses). Angles in the 16-membered ring are 119.2(1) and 115.1(1)° at P and 131.5(1) and 148.2(1)° at N.

The preparation and the crystal and molecular structure of tetradecamethylcycloheptaphosphazene, (NPMe2)7

1977 ◽  
Vol 55 (2) ◽  
pp. 304-309 ◽  
Author(s):  
Keith D. Gallicano ◽  
Richard T. Oakley ◽  
Norman L. Paddock ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Membered Ring ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths ◽  
The Mean

The preparation of tetradecamethylcycloheptaphosphazene, by the methylation of the corresponding fluorophosphazene (NPF2)7 with methylmagnesium bromide, is reported. Crystals of tetradecamethylcycloheptaphosphazene are monoclinic, a = 13.160(1), b = 11.685(1), c = 18.576(1) Å, (β = 108.333(5)°, Z = 4, space group C2/c. The structure was solved by direct methods and was refined by full-matrix least squares procedures to a final R of 0.046 and Rw of 0.063 for 2568 reflections with I ≥ 3σ(I). The molecule has crystallographic C2 symmetry with mean bond lengths (rms deviations from the mean in parentheses, bonds not involving hydrogen have been corrected for libration) P—N, 1.592(6), P—C, 1.804(11), and C—H, 0.94(7) Å, and mean angles in the 14-membered ring are 132.9° at N and 117.1° at P.

Crystal and molecular structure of dodecamethylcyclohexaphosphazene, (NPMe2)6

1977 ◽  
Vol 55 (17) ◽  
pp. 3118-3123 ◽  
Author(s):  
Richard T. Oakley ◽  
Norman L. Paddock ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Unit Cell ◽  
Weighted Mean ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths ◽  
The Mean

Crystals of dodecamethylcyclohexaphosphazene are triclinic, a = 13.898(1), b = 8.690(1), c = 10.790(1) Å, α = 109.84(1), β = 92.01(1), γ = 106.39(1)°, Z = 2, space group [Formula: see text]. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to a final R of 0.034 and Rw of 0.042 for 4217 reflections with I ≥ 3σ(I). The unit cell contains two independent centrosymmetric molecules which are virtually identical. The 12-membered rings have the 'double tub' conformation. Bond lengths not involving hydrogen have been corrected for libration. Weighted mean bond lengths (rms deviations from the mean in parentheses) are: P—N, 1.593(6), C—P, 1.808(4), and C—H, 0.95(6) Å.

Crystal and Molecular Structure of 4,4-Dimethyl-2,2-diphenyl-1,3-dioxa-4-azonia-2- boranatacyclopentane

1974 ◽  
Vol 52 (14) ◽  
pp. 2531-2541 ◽  
Author(s):  
Steven J. Rettig ◽  
James Trotter ◽  
W. Kliegel
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Van Der Waals ◽  
Direct Methods ◽  
Chair Conformation ◽  
Membered Ring ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths

Crystals of 4,4-dimethyl-2,2-diphenyl-1,3-dioxa-4-azonia-2-boranatacyclopentane are orthorhombic, a = 17.043(3), b = 6.289(1), c = 13.024(2) Å, Z = 4, space group Pna21. The structure was determined by direct methods, and was refined by full-matrix least-squares procedures to R = 0.071 for 1100 reflections with I ≥ 3σ(I). Bond angles in the five-membered ring, which has a distorted half-chair conformation, range from 101.5(4) for OBO to 107.1(4)° for NOB. Bond lengths are: mean B—C, 1.632(8), B—O, 1.506(7) and 1.556(8), N—O, 1.409(5), C—O, 1.378(9), C—N, 1.467–1.509(7–10), mean C—C(aromatic), 1.395(25) Å. The structure consists of discrete molecules separated by normal van der Waals distances.

Crystal and molecular structure of (salicylaldehydato)diphenylboron

1976 ◽  
Vol 54 (7) ◽  
pp. 1168-1175 ◽  
Author(s):  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Thermal Motion ◽  
Hydrogen Atoms ◽  
Weighted Mean ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths

Crystals of (salicylaldehydato)diphenylboron are orthorhombic, a = 11.6548(5), b = 16.2983(5), c = 8.0806(2) Å, Z = 4, space group Pna21. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to a final R of 0.051 for 1386 reflections with I ≥ 3σ(I). The BO2C3 ring has a distorted 'sofa' conformation. Bond lengths in the molecule (those not involving hydrogen atoms have been corrected for thermal motion) are: C—O, 1.263(4) and 1.334(4), B—O, 1.500(4) and 1.574(4), C—B, 1.603(5) and 1.610(5), C—C(salicylaldehyde), 1.368–1.423(5–8), C—C(phenyl), 1.352–1.413(5–11), and weighted mean C(sp2)—H, 0.96 Å.

Crystal and molecular structure of difluoroboron N-methylacethydroxamate (2,2-difluoro-4,5-dimethyl-1,3-dioxa-4-azonia-2-boranatacyclopent-4-ene)

1977 ◽  
Vol 55 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Steven J. Rettig ◽  
James Trotter ◽  
W. Kliegel ◽  
D. Nanninga
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths

Crystals of difluoroboron N-methylacethydroxamate are monoclinic, a = 5.097(1), b = 10.653(2), c = 11.520(2) Å, β = 103.57(2)°, Z = 4, space group P21/c. The structure was solved by direct methods and was refined by full-matrix least squares procedures to a final R of 0.056 and Rw of 0.077 for 988 reflections with I ≥ 3σ(I). The structure features a planar five-membered BO2CN ring. Bond lengths (corrected for libration) are: B—F, 1.374(3) and 1.381(3), O—B, 1.496(3) and 1.497(3), O—N, 1.349(2), O—C, 1.346(2), C—N, 1.298(3) and 1.458(3), and C—C, 1.468(3) Å.

Crystal and molecular structure of L-prolinatodiphenylboron

1977 ◽  
Vol 55 (6) ◽  
pp. 958-965 ◽  
Author(s):  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Conformational Disorder ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths

Crystals of L-prolinatodiphenylboron are monoclinic, a = 5.9427(5), b = 14.4633(7), c = 8.9654(4) Å, β = 98.423(8)°, Z = 2, space group P21. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to a final R of 0.037 and Rw of 0.053 for 1477 reflections with I ≥ 3σ(I). The proline ring exhibits conformational disorder. The crystal structure consists of discrete molecules linked by N—H … O hydrogen bonds (N … O = 2.893(3) Å) along the short a axis. Intramolecular N—B coordination occurs to form a system of two fused five-membered rings. Bond lengths (corrected for libration) are: N—B, 1.630(3), O—B, 1.529(3), O—C, 1.219(3) and 1.300(3), N—C, 1.506(3) and 1.507(3), C(sp3)–C(sp3), 1.525(4), C(sp2)—C(sp3), 1.517(3), and mean C—C(phenyl), 1.394 Å.

Crystal and molecular structure of diphenylboron N-methylacethydroxamate (4,5-dimethyl-2,2-diphenyl-1,3-dioxa-4-azonia-2-boratacyclopent-4-ene)

1978 ◽  
Vol 56 (12) ◽  
pp. 1676-1680 ◽  
Author(s):  
Steven J. Rettig ◽  
James Trotter ◽  
W. Kliegel ◽  
D. Nanninga
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Heterocyclic Ring ◽  
Mirror Plane ◽  
Full Matrix ◽  
Space Group ◽  
Carbon And Nitrogen ◽  
Bond Lengths

Crystals of diphenylboron N-methylacethydroxamate are orthorhombic, a = 12.5478(8), b = 7.8735(3), c = 13.6809(5) Å, Z = 4, space group Pnam. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.037 and Rw = 0.054 for 1265 reflections with I ≥ 3σ(I). The molecule features a five-membered BO2CN ring which lies in the crystallographic mirror plane. The carbon and nitrogen atoms of the heterocyclic ring are positionally disordered. Mean bond lengths (corrected for libration) are: O—B, 1.550(2), B—C, 1.609(2), O—C/N, 1.340(3), C—N, 1.300(2), C/N—CH, 1.470(2), and C—C(phenyl), 1.394(8) Å.

Crystal and Molecular Structure of B-Phenyl-diptychboroxazolidine,

1975 ◽  
Vol 53 (10) ◽  
pp. 1393-1401 ◽  
Author(s):  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Thermal Motion ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths

Crystals of B-phenyl-dictychboroxazolidine are monoclinic, a = 8.4977(4), b = 9.0617(5), c = 7.0105(3) Å, β = 111.627(3)°, Z = 2, space group P21. The structure was solved by direct methods and was refined by full-matrix least squares procedures to a final R of 0.040 for 967 reflections with I ≥ 3σ(I). The bond lengths involving nonhydrogen atoms have been corrected for thermal motion. Bond lengths are: B—O, 1.460(3) and 1.474(3), B—N, 1.666(3), B—C, 1.613(3), C—O, 1.411(3) and 1.419(3), C—N, 1.485(3) and 1.486(3), C(sp3)—C(sp3), 1.514(4) and 1.524(4), C—C(ar), 1.384–1.400(4–6), mean C—H, 0.98(4), and N—H, 0.87(5) Å. The crystal structure consists of discrete molecules of B-phenyl-diptychboroxazolidine each linked to two others by N—H … O hydrogen bonds (O … N = 2.914(3) Å) to form continuous spirals along b.

Crystal and Molecular Structure of Hexakis(dimethylamino)cyclotriphosphazene, [NP(NMe2)2]3

1973 ◽  
Vol 51 (8) ◽  
pp. 1295-1302 ◽  
Author(s):  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Electron Density ◽  
Title Compound ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Full Matrix ◽  
Space Group ◽  
The Mean

Crystals of the title compound are monoclinic, a = 15.539(4), b = 9.061(1), c = 16.707(6) Å, β = 107.19(5)°, Z = 4, space group P21/c. The measured and calculated densities are 1.19 and 1.180(1) g cm−3, respectively. The structure was determined by direct methods and refined by electron-density and full-matrix least-squares procedures to R = 0.047 for 2503 observed reflections. The six-membered phosphazene ring is slightly, but significantly, non-planar, the conformation being that of a distorted boat. The molecule has approximate D3 symmetry. The ring P—N bonds are all equal, mean P—N = 1.588(3) Å, and the relatively short exocyclic P—N bonds, mean 1.652(4) Å, indicate the presence of exocyclic π-bonding in the molecule. The N—C bonds range from 1.417(7) to 1.471(5) with a mean of 1.45(2) Å. The mean endocyclic N—P—N and P—N—P angles are 116.7(4) and 123.0(4)°, respectively, while the exocyclic N—P—N angles average 101.5(8)°.

Crystal and molecular structure of 1,1′-bi(3,3,4,4-tetrafluoro-2-diphenylphosphinocyclobutene)

1977 ◽  
Vol 55 (17) ◽  
pp. 3065-3070 ◽  
Author(s):  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Molecular Symmetry ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths ◽  
Good Agreement

Crystals of 1,1′-bi(3,3,4,4-tetrafluoro-2-diphenylphosphinocyclobutene) are monoclinic, a = 10.398(1), b = 18.484(1), c = 15.984(1) Å, β = 107.76(1)°, Z = 4, space group P21/c. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to a final R of 0.042 and Rw of 0.057 for 4226 reflections with I ≥ 3σ(I). The molecule has a cisoid configuration about the central C—C bond, the angle between the two cyclobutene rings being 34.3°. The overall molecular symmetry is approximately C2 with a P … P separation of 3.661(1) Å. Bond lengths and angles in the molecule are generally in good agreement with accepted values.

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