scholarly journals Crystal and molecular structure of 2,2,4,6,6-pentamethyl-5-benzoyl-4-(N-methylbenzamido)-1,3-diaza-2,4,6(Pv)-triphosphorin

1977 ◽  
Vol 55 (13) ◽  
pp. 2534-2539 ◽  
Author(s):  
Richard T. Oakley ◽  
Norman L. Paddock ◽  
Steven J. Rettig ◽  
James Trotter

Crystals of 2,2,4,6,6-pentamethyl-5-benzoyl-4-(N-methylbenzamido)-1,3-diaza-2,4,6(Pv)-tri-phosphorin are triclinic, a = 13.375(1), b = 11.313(1), c = 7.925(1) Å, α = 107.72(1), β = 98.23(1), γ = 87.00(1)°, Z = 2, space group [Formula: see text]. The structure was solved by Patterson and Fourier syntheses and was refined by full-matrix least-squares procedures to a final R of 0.067 and Rw of 0.089 for 3954 reflections with. I ≥ 3σ(I) The P3N2C ring is nearly planar and has a conformation corresponding to a flattened version of the chair – twist boat. Bond lengths in the azaphosphorin ring, P—N, 1.579–1.614(2), and P—C, 1.752(3) and 1.777(3) Å, indicate conjugation with the C-benzoyl group. The exocyclic P—N bond length, 1.742(3) Å, is longer than those in related compounds as a result of competitive electron withdrawal from the N-benzoyl group. Other bond lengths (corrected for libration) are: mean P—Me, 1.796(4); C=O, 1.242(3) and 1.247(4); C—N, 1.472(3) and 1.369(4); mean C—C(phenyl), 1.391(10); other C(sp2)—C(sp2); 1.417–1.518(4) Å.


1978 ◽  
Vol 56 (10) ◽  
pp. 1364-1367 ◽  
Author(s):  
M. J. Bennett ◽  
J. T. Purdham

1,2,4,5-Tetraphenyl-3,6-dicarbornethoxytricyclo[3.1.0.02,4]hexane crystallizes in the monoclinic space group P21/c with a = 10.044(4), b = 9.500(2), c = 14.172(4) Å, β = 104.38(2)°, and Z = 2. Using 1032 unique reflections with I > 3σ(I), the structural data were refined by full matrix least-squares techniques to R = 0.038. The molecule was found to be in the anti-configuration. All bond lengths within the highly strained central tricyclic framework were equal within experimental error and average 1.531 Å.



1977 ◽  
Vol 55 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Steven J. Rettig ◽  
James Trotter ◽  
W. Kliegel ◽  
D. Nanninga

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.



1975 ◽  
Vol 53 (5) ◽  
pp. 777-783 ◽  
Author(s):  
Steven J. Rettig ◽  
James Trotter

Crystals of 2,5-bis(2′-hydroxyethylamino)-1,4-benzoquinone are monoclinic, a = 5.020(1), b = 19.238(3), c = 5.214(1) Å, β = 96.15(3)°, Z = 2, space group P21/n. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to a final R of 0.045 for 646 reflections with I ≥ 3σ(I). The benzoquinone ring in the centrosymmetric molecule is slightly, but significantly, nonplanar. Bond distances in the compound (C—C, 1.247 (2) and 1.410 (3), C—N, 1.332 (3) and 1.457 (3), C—C, 1.384–1.514 (3), N—H, 0.89 (3), O—H, 1.07 (5), and C—H, 0.95–1.09 (3) Å) are similar to those in related compounds. The structure features an extensive network of N—H … O (N … O = 2.639 (3) and 3.033 (2) Å) and O—H … O(O … O = 2.757 (3) Å ) hydrogen bonds.



1988 ◽  
Vol 66 (3) ◽  
pp. 355-358 ◽  
Author(s):  
Steven J. Rettig ◽  
Alan Storr ◽  
James Trotter

Crystals of [dimethyl(1-pyrazolyl)(2-pyridylmethoxy)gallato-N2,O,N3](η3-allyl)dicarbonylmolybdenum(II) are triclinic, a = 9.632(2), b = 9.798(2), c = 10.255(2) Å, α = 80.16(1), β = 87.38(1), γ = 81.75(1)°, Z = 2, space group [Formula: see text]. The structure was solved by conventional heavy-atom methods and was refined by full-matrix least-squares procedures to R = 0.033 and Rw = 0.037 for 3000 reflections with I ≥ 3σ(I). The molecule has pseudo-octahedral coordination geometry with the tridentate [Me2Ga(N2C3H3)(OCH2(C5H4N))]− ligand facially coordinated and the η3-allyl ligand occupying one coordination site trans to the pyridyl nitrogen atom. Important bond lengths are Mo—O = 2.219(2), Mo—N(py) = 2.212(3), Mo—N(pz) = 2.232(2), Mo—C(allyl) = 2.290(4), 2.189(4), 2.341(4), Mo—CO (trans to O) = 1.928(4), and Mo—CO (trans to N) = 1.952(4) Å.



1977 ◽  
Vol 55 (6) ◽  
pp. 958-965 ◽  
Author(s):  
Steven J. Rettig ◽  
James Trotter

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.



1974 ◽  
Vol 52 (17) ◽  
pp. 2985-2989
Author(s):  
James C. Barrick ◽  
Crispin Calvo ◽  
Fredric P. Olsen

The crystal and molecular structure of benzylidenimine disulfide has been determined. Crystals are monoclinic with space group P21/c, Z = 4, a = 12.93(2), b = 5.554(9), c = 20.46(3) Å, and β = 112.5(2)°. A full matrix least squares refinement on 2304 unique reflections of positive intensity measure collected on a [Formula: see text] Automatic diffractometer produced a conventional R of 0.029. The molecular geometry is very similar to that in the corresponding tetra- and trisulfides with a fairly short sulfur–sulfur bond length of 2.033(2) Å and a fairly long sulphur–nitrogen bond length of 1.690(3) Å.



1978 ◽  
Vol 56 (12) ◽  
pp. 1676-1680 ◽  
Author(s):  
Steven J. Rettig ◽  
James Trotter ◽  
W. Kliegel ◽  
D. Nanninga

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.



1978 ◽  
Vol 56 (7) ◽  
pp. 891-895 ◽  
Author(s):  
Frederick W. B. Einstein ◽  
Derek Sutton ◽  
Peter L. Vogel

The title compound crystallizes in the space group P21/c with four formula units in a cell of dimensions a = 10.146(6) Å, b = 10.593(4) Å, c = 26.31(1) Å, β = 103.14(3)°. Using 1496 observed reflections (I = 2.3σ(I)) in the range 0° < 2θ < 40° measured on a Picker FACS-1 automatic diffractometer with Mo-Kα radiation, the structure was solved (symbolic addition) and refined (full-matrix least-squares procedure) to R = 0.062 (Rw = 0.058), with all hydrogen atoms included and all non-hydrogen atoms having anisotropic thermal parameters. The dimensions within the cation are consistent with a delocalized electronic structure which is intermediate between valence formulations involving benzenoid or quinonoid structures for the (4-diethylaminophenyl)diazenyl residue. Some important bond lengths are N3—C22 1.336(7) Å, N2—C19 1.356(7) Å, N1—N2 1.308(6) Å, and P—N1 1.648(5) Å.



1983 ◽  
Vol 61 (3) ◽  
pp. 541-544 ◽  
Author(s):  
Norman L. Paddock ◽  
Steven J. Rettig ◽  
James Trotter

Crystals of hexadecamethylcyclooctasiloxane are tetragonal, a = 13.9442(5), c = 8.5573(4) Å, Z = 2, space group P4/nnc. 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 = 0.042 for 730 reflections with I ≥ 3σ(I). The molecular structure closely resembles that of [(CH3)2PN]8. Its comparatively rigid conformation, in which the silicon atoms form a crown, is dependent on the efficient use of van der Waals interactions between two sets of four methyl groups. Important molecular dimensions (bond lengths corrected for libration) are: Si—O = 1.629(1) and 1.635(1), Si—C = 1.862(2) and 1.848(3) Å, O—Si—O = 108.99(6), Si—O—Si = 157.8(1) and 148.8(2)°.



1973 ◽  
Vol 51 (22) ◽  
pp. 3691-3696 ◽  
Author(s):  
James C. Barrick ◽  
Crispin Calvo ◽  
Fredric P. Olsen

The structure of the title compound has been determined. Crystals are monoclinic with space group P21/a, Z = 4, a = 13.83(1), b = 19.66(2), c = 5.983(5) Å, β = 101.4(1)°, dcalcd = 1.404, dobs = 1.40(1). A full-matrix least-squares refinement on 1085 unique reflections of positive intensity measure produced a conventional R of 0.066. The spiral arrangement of the S4 chains (nearly generating a 31 axis) is such that the two aromatic rings are eclipsed. Alternation in bond length along the sulfur chain was observed, the long inner bond being 2.083(4) Å and the shorter outer bonds averaging 2.026(3) Å in length. No intermolecular non-bonding interactions involving sulfur were found.



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