The cycloaddition of norbornadiene to (triphenylphosphoranediyl)aminocyclotrithiatriazene; the crystal and molecular structure of Ph3PN—S3N3•C7H8

1983 ◽  
Vol 61 (9) ◽  
pp. 2062-2067 ◽  
Author(s):  
Stephen W. Liblong ◽  
Richard T. Oakley ◽  
A. Wallace Cordes ◽  
Mark C. Noble
Keyword(s):  
Molecular Structure ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Chair Conformation ◽  
Monoclinic Space Group ◽  
Frontier Orbitals ◽  
Full Matrix ◽  
X Ray ◽  
X Ray Crystallography ◽  
Kinetics Of

The reaction of norbornadiene with (triphenylphosphoranediyl)aminocyclotrithiatriazene produces the cycloadduct Ph3PN—S3N3•C7H8. The crystal and molecular structure of this compound has been determined by X-ray crystallography. Crystals of Ph3PN—S3N3•C7H8 are monoclinic, space group P21/c, a = 9.757(1), b = 15.114(1), c = 16.535(2) Å, β = 100.73(1)°, V = 2395.7(9) Å3, and Z = 4. The structure was solved by direct methods and refined by Fourier and full-matrix least-squares procedures to give a final R of 0.040 and Rw of 0.058 for 2620 observed reflections. The structure reveals that the S3N3 ring adds to norbornadiene in an exo fashion via two sulphur atoms. The S3N3 ring adopts a chair conformation with the three ligands occupying axial positions on the same side of the ring. The relative rates of this and other cycloadditions involving SN substrates and olefins are discussed in terms of the energies of the interacting frontier orbitals. The results suggest that HOMO(olefin)–LUMO(SN substrate) interactions control the kinetics of these reactions.

The crystal and molecular structure of 1,4-diphenyl-2,2′,3,3′,5,5′,6,6′-octamethylcyclo-1,4-diphospha-2,3,5,6-tetrasilahexane, a phosphorus–silicon heterocycle

1979 ◽  
Vol 57 (2) ◽  
pp. 174-179 ◽  
Author(s):  
A. Wallace Cordes ◽  
Paul F. Schubert ◽  
Richard T. Oakley
Keyword(s):  
Molecular Structure ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Chair Conformation ◽  
Monoclinic Space Group ◽  
Single Bond ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
Bond Lengths

The crystal structure of 1,4-diphenyl-2,2′,3,3′,5,5′,6,6′-octamethylcyclo-1,4-diphospha-2,3,5,6-tetrasilahexane, (PhPSi2Me4)2, has been determined by single crystal X-ray diffraction. The crystals are monoclinic, space group P21/c, with a = 9.866(1), b = 11.921(1), and c = 11.324(2) Å, β = 104.31(1)°, Z = 2, and ρcalcd = 1.15 g/cm3. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to a final R of 0.060 and Rw of 0.078, for 1173 reflections with intensities greater than 3σ. The (PhPSi2Me4)2 molecule lies on a crystallographic centre of symmetry, and the six-membered P2Si4 ring has a chair conformation with equatorial phenyl groups. The endocyclic angles at P (104.4(1)°) and Si (104.9(2)°) are intermediate between those found in cyclic hexaphosphine and hexasilane molecules, and the Si—Si and P—Si distances of 2.345(3) and 2.252(4) Å, respectively, correspond to single bond lengths, with no appreciable evidence for secondary pπ → dπ bonding between phosphorus and silicon. The Si—C (1.867(8) Å) and P—C (1.828(7) Å) bond lengths are also normal. The variations in the Si—P—C (101.6(2)°, 108.6(2)°), P—Si—C (range 106.2(3)–120.0(3)°), and Si—Si—C (range 105.8(3)–113.7(3)°) angles indicate that the positions of the exocyclic methyl and phenyl groups are influenced by both intra- and intermolecular steric forces.

The reaction of tetrasulphur dinitride with norbornadiene; the crystal and molecular structure of S4N2•C7H8, an eight-membered C2S4N2 heterocycle

1983 ◽  
Vol 61 (6) ◽  
pp. 1185-1188 ◽  
Author(s):  
Hans Koenig ◽  
Richard T. Oakley ◽  
A. Wallace Cordes ◽  
Mark C. Noble
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Dihedral Angle ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Crystallographic Analysis ◽  
Monoclinic Space Group ◽  
Full Matrix ◽  
Space Group ◽  
X Ray

The reaction of tetrasulphur dinitride with norbornadiene produces the 1:1 adduct S4N2•C7H8; X-ray crystallographic analysis of this compound reveals that olefin addition cleaves one of the sulphur–sulphur bonds of S4N2, yielding a novel eight-membered C2S4N2 ring. Crystals of S4N2•C7H8 are monoclinic, space group P21/c, a = 6.127(1), b = 17.369(1), c = 9.580(1) Å, β = 106.74(1)°, V = 1003.8(5) Å3Z = 4. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.039. The S—S—N—S—N—S fragment of the C2S4N2 ring is planar to within 0.15 Å. The S—C—C—S unit is folded out of this plane to produce a dihedral angle of 74.5°.

Weak interactions observed in ruthenium and iridium complexes containing hydride, amine, and bulky phospyhine ligands

1997 ◽  
Vol 75 (5) ◽  
pp. 475-482 ◽  
Author(s):  
Wei Xu ◽  
Alan J. Lough ◽  
Robert H. Morris
Keyword(s):  
Molecular Structure ◽  
Crystal And Molecular Structure ◽  
Weak Interactions ◽  
Crystal Structure Analysis ◽  
Monoclinic Space Group ◽  
Iridium Complexes ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
Van Der Waals Contacts

New amineruthenium and amineiridium hydride derivatives have been synthesized and characterized with the objective of observing intramolecular [Formula: see text] or [Formula: see text] interactions. These include RuHCl(CO)(L)(PPri3)2 (1a, L = NH2NH2; 1b, L = NH3) and IrCl2(L)(H)(PCy3)2 (2a, L = SC(NH2)2; 2b, L = NH3; 2c, L = NH2NH2; 2d, L = NH2(CH2)3NH2; 2e, L = NH2OH). Instead, weak [Formula: see text] van der Waals contacts have been detected in the solid state by X-ray analysis and in solution by NMR T1 measurements and nOe techniques. Both X-ray crystal structure analysis and minimum T1 measurements indicate that the [Formula: see text] distances in the [Formula: see text] interactions are ca•2.0–2.2 Å. The weak interactions might influence the course of deuteration of these complexes under D2 gas. The crystal and molecular structure of IrCl2(NH3)(H)(PCy3)22a has been determined by X-ray diffraction at 173 K: monoclinic, space group P21/n, a = 14.859(2) Å, b = 18.579(3) Å, c = 18.548(3) Å, β = 97.29(1)°, V = 5079.1(13) Å3, Z = 4, full-matrix least-squares refinement on F2 for 10 953 independent reflections; R[F2 > 4σ(F2)] = 0.0283, wR(F2) = 0.0704. Keywords: ruthenium, iridium, hydride, dihydrogen, complexes, hydrogen bond, NMR, X-ray.

Nitrones and oximes of bifunctional carbonyl compounds and their reaction products with diarylborinic acids. Crystal and molecular structure of examples of five-, six-, and seven-membered boron chelates

2000 ◽  
Vol 78 (10) ◽  
pp. 1325-1344
Author(s):  
Wolfgang Kliegel ◽  
Gottfried Lubkowitz ◽  
Jens O Pokriefke ◽  
Steven J Rettig ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Carbonyl Compounds ◽  
Spectroscopic Data ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Reaction Products ◽  
Boron Chelates ◽  
Full Matrix ◽  
Space Group ◽  
X Ray

Synthesis has been carried out of diarylboron chelates of 2- and 3-hydroxynitrones, of 2- and 3-hydroxyoximes, and of 2-carboxynitrones and a 2-carboxyoxime. The structures have been determined from spectroscopic data and from X-ray analyses of 5d, 9a, 11b, and 19. Crystals (at 180 K) of 5d are monoclinic, a = 10.543(2), b = 19.085(4), c = 10.2667(3) Å, β = 90.4978(7)°, Z = 4, space group P21/c; those of 9a are orthorhombic, a = 10.9913(5), b = 14.9329(7), c = 10.2460(13) Å, Z = 4, space group P212121; those of 11b are monoclinic, a = 11.227(2), b = 9.967(2), c = 17.0537(4) Å, β = 105.4179(5)°, Z = 4, space group P21/n; those of 19 are monoclinic, a = 11.1847(15), b = 13.715(3), c = 11.5559(5) Å, β = 104.8730(10)°, Z = 4, space group P21/n. The structures were solved by direct methods and refined by full-matrix least-squares procedures to R(F, I [Formula: see text] 3σ(I)) = 0.049, 0.047, 0.042, and 0.047, respectively, for CCD data for 5d, 9a, 11b, and 19. The four molecules contain five-, seven-, six-, and five-membered rings, respectively, with O-B-N groups in the 5d, 11b, and 19, and O-B-O in 9a; the rings exhibit various deviations from planarity, particularly the seven-membered ring.Key words: diarylboron chelates, hydroxyoximes, hydroxynitrones, carboxyoximes, carboxynitrones, organoboron compounds, crystal structure.

Structural studies of organoboron compounds. LX. Reaction of sterically hindered arylboronic acids with 2-(hydroxyamino)alkanols. Crystal and molecular structure of 2-mesityl-6,6-pentamethylene-1,3-dioxa-4-aza-2-boracyclohexane

1994 ◽  
Vol 72 (4) ◽  
pp. 1154-1161 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Gottfried Lubkowitz ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Structural Studies ◽  
Full Matrix ◽  
Space Group ◽  
X Ray ◽  
Arylboronic Acids ◽  
Sterically Hindered

Three 2-(hydroxyamino)alkanols have been reacted with sterically hindered arylboronic acids, ArB(OH)2. When Ar = o-tolyl, 1:2 condensates having bicyclic structures are formed but when Ar = mesityl (2,4,6-(CH3)3C6H2), 1:1 condensates having six-membered cycloboronate structures result. These 1:1 condensates represent the first examples of N-unsubstituted 1,3-dioxa-4-aza-2-boracyclohexane derivatives. An X-ray analysis of one example provides unambiguous proof of the structure. Crystals of 2-mesityl-6,6-pentamethylene-1,3-dioxa-4-aza-2-boracyclohexane, 3c, are monoclinic, a = 11.076(9), b = 23.94(2), c = 13.414(9) Å, β = 109.40(5)°, Z = 8, space group P21/n. The structure was solved by direct methods and refined by full-matrix least-squares procedures to R = 0.051 and Rw = 0.058 for 2037 reflections with I ≥ 3σ(F2).

Structure and Conformation of Photosynthetic Pigments and Related Compounds, 8 [1]Molecular Structure of an Iron(III) Chlorophyll Derivative-Chloro(phytochlorinato methyl ester)iron(III)

1995 ◽  
Vol 50 (1) ◽  
pp. 139-146 ◽  
Author(s):  
Mathias O. Senge ◽  
Karin Ruhlandt-Senge ◽  
Kevin M. Smith
Keyword(s):  
Molecular Structure ◽  
Crystal And Molecular Structure ◽  
Axial Ligand ◽  
Monoclinic Space Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
Chlorophyll Derivative ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
Related Compounds

The crystal and molecular structure of chloro(methyl phytochlorinato)iron(III), 4, have been determined by single crystal X-ray crystallography to obtain further information on the conformation of metallochlorins related to chlorophyll. The compound crystallized with two independent molecules mainly distinguished by the orientation of the axial ligand. The macrocycles show significant deviations from planarity larger than those observed in corresponding magnesium(II) complexes. The overall type of distortion is similar to those found in chlorophyllides. Compound 4 crystallized in the monoclinic space group P21 (MoKa,λ = 0.71063 A) with unit cell dimensions a = 12.035(6) Å, b = 13.396(8) Å, c = 19.04(2), b = 97.51(2) Å, Z = 4, V = 3043(4) Å3. The structure was refined to an R-value of 0.075 on the basis of 3974 reflections with I > 3.0σ(Ι) (130 Κ).

The Crystal and Molecular Structure of Chloro-mer-Tris(dimethylphenylphosphine)-cis-dihydridoiridium(III) by X-Ray and Neutron Diffraction

1988 ◽  
Vol 41 (5) ◽  
pp. 641 ◽  
Author(s):  
GB Robertson ◽  
PA Tucker
Keyword(s):  
Molecular Structure ◽  
Neutron Diffraction ◽  
Single Crystal ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Monoclinic Space Group ◽  
Neutron Data ◽  
Full Matrix ◽  
Space Group ◽  
X Ray

The structure of mer-(Pme2Ph)3Cl-cis-H2IrIII (1) has been determined by single-crystal X-ray and neutron diffraction analyses. Crystals are monoclinic, space group P21, with a 11.476(4), b 14.069(5), c 8.286(3)Ǻ, β 92.45(1)° and Z 2. Full-matrix least-squares analyses converged 0.022 for 7773 X-ray data and R(F2) = 0.062 for 1538 neutron data. Ir -H [1.557(11)Ǻ trans to Cl, 1.603(10) Ǻ trans to P] and Ir -P distances [2.292(1)Ǻ trans to P, 2.328(1)Ǻ trans to H] both exhibit trans lengthening effects. Consistent with the increased hydride content the Ir -P distances in (1) are c. 0.04 Ǻ shorter than for the corresponding bonds in its dichloro monohydrido analogues and c. 0.08 Ǻ shorter than those in the trichloride . In contrast Ir-Cl [2.505(1)Ǻ] is not significantly different to the corresponding distance (2.504 Ǻ av.) in mer -(PMe2Ph)3-cis-Cl2HIrIII.

Crystal and molecular structure of 4α-t-Butylcyclohexane-1β,2β-diol

1972 ◽  
Vol 25 (10) ◽  
pp. 2117 ◽  
Author(s):  
MD Brice ◽  
BR Penfold ◽  
WT Robinson
Keyword(s):  
Molecular Structure ◽  
Crystal And Molecular Structure ◽  
Chair Conformation ◽  
Intensity Data ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
Full Matrix ◽  
X Ray ◽  
R Factor ◽  
Least Squares Techniques

The crystal and molecular structure of 4α-t-butylcyclohexane-1β,2,β-diol, C10H20O2, has been determined by X-ray diffraction methods. The compound crystallizes in the triclinic space group Pi with 4 molecules in a unit cell of dimensions a = 12.268, b = 15.921, c = 6.322�, α = 82.53, β = 114.45, γ = 111.13�. The intensity data were measured by counter methods using Cu Kα radiation; the structure was solved by means of the tangent formula, and was refined using full matrix least-squares techniques to a final R-factor of 0.063 for 1199 reflections. The crystal structure consists of two sets of crystallographically non-equivalent molecules hydrogen-bonded to form discrete chains parallel to the c axis. The cyclohexane rings are in the chair conformation.

The crystal and molecular structure of a platinum-silatrane complex

1977 ◽  
Vol 30 (5) ◽  
pp. 1007 ◽  
Author(s):  
GR Scollary
Keyword(s):  
Molecular Structure ◽  
Structural Analysis ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
Space Group ◽  
X Ray

A structural analysis of the platinum-silatrane complex, PtCl [Si(OCH2CH2)3N] [PMe2Ph]2, has been carried out by X-ray diffraction. Crystals are monoclinic, space group P21/c, a 6.630(4), b 17.465(6), c 22.297(6) Ǻ, β 97.4(2)�, Z 4. The structure has been refined by a full- matrix least-squares procedure to R 0.048 for 2165 reflections. Basic geometries are square (platinum), tetrahedral (silicon) and trigonal (nitrogen). Within the silatrane ligand, the Si-N non-bonding distance is 2.89(1) Ǻ.

The Crystal and Molecular Structure of trans-Dichloro-mer-trans-bis (triisopropylphosphine)(phosphine)hydridoiridium(III)

1995 ◽  
Vol 48 (7) ◽  
pp. 1277 ◽  
Author(s):  
EJ Ditzel ◽  
GB Robertson
Keyword(s):  
Molecular Structure ◽  
Transition Metal ◽  
Crystal And Molecular Structure ◽  
Structure Refinement ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Hydrogen Atoms ◽  
Full Matrix ◽  
X Ray ◽  
Molecular Dimensions

The structure of mer-trans-(PPri3)2(PH3)H-trans-Cl2IrIII (1) (Pri = isopropyl), the second third-row transition-metal-PH3 complex to be so characterized, has been determined by single-crystal X-ray diffraction analysis. Crystals are monoclinic, space group C 2/c with a 21.701(2), b 8.735(1), c 15.594(1) Ǻ, β 119.57(1)° and Z 4. Structure refinement by full-matrix least-squares analysis (2811 reflections, 113 parameters) converged with R = 0.016 and Rw = 0.022. Molecules exhibit crystallographically imposed C2 symmetry. The C2 axis passes through the iridium, hydride and PH3 phosphorus atoms, and requires the PH3 hydrogen atoms to be disordered. Important molecular dimensions are Ir-PPri3 2.371(1) Ǻ, Ir-PH3 2.362(1) Ǻ, Ir-Cl 2.374(1) Ǻ and P- Ir -P(trans) 163.21(3)°.

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