Structural studies of organoboron compounds. XXXII. 5,5-Difluoro-2,2-pentamethylene-1,4,6-trioxa-3a-azonia-5-borata-1,2,3,4,5,6-hexahydrobenzo[h]azulene and 2,2-pentamethylene-5,5-diphenyl-1,4,6-trioxa-3a-azonia-5-borata-1,2,3,4,5,6-hexahydrobenzo[h]azulene

1988 ◽  
Vol 66 (10) ◽  
pp. 2621-2630 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Mahmood Tajerbashi ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Solid State ◽  
Physical Properties ◽  
Least Squares ◽  
Crystal Structures ◽  
Direct Methods ◽  
Structural Studies ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths ◽  
Conformational Isomers

Details of the syntheses, physical properties, and crystal structures of the title compounds are reported. Crystals of 5,5-difluoro-2,2-pentamethylene-1,4,6-trioxa-3a-azonia-5-borata-1,2,3,4,5,6-hexahydrobenzo[h]azulene are triclinic, a = 6.1576(3), b = 11.2651(3), c = 10.8118(3) Å, α = 109.747(3), β = 105.807(4), γ = 92.976(4)°, Z = 2, space group [Formula: see text], and those of 2,2-pentamethylene-5,5-diphenyl-1,4,6-trioxa-3a-azonia-5-borata-1,2,3,4,5,6-hexahydrobenzo[h]azulene are monoclinic, a = 9.8549(6), b = 10.9242(6), c = 41.263(2) Å, β = 92.717(6)°, Z = 8, space group P21/n. Both structures were solved by direct methods and were refined by full-matrix least-squares procedures to R = 0.045 and 0.042 for 2344 and 4248 reflections with I ≥ 3σ(I), respectively. The molecules were both found to possess a seven-membered chelate structure, the O,O-chelatїng ligand being strongly bound to the X2B moiety. Two conformational isomers of the X = Ph compound were found in the solid state. The 2-oxazoline N-oxide moieties present in both compounds are the first to be structurally characterized. Important mean libration-corrected bond lengths are: O—B = 1.491 and F—B = 1.387 Å for X = F; O—B = 1.511 and C—B = 1.620 Å for X = Ph.

Structural studies of organoboron compounds. XXXIV. 4-(N-Methoxymethylimino)-2,2-diphenyl-1,3-dioxa-2-borata-1,2,3,4-tetrahydronaphthalene and 4-diethylimino-2,2-diphenyl-1,3-dioxa-2-borata-1,2,3,4-tetrahydronaphthalene

1989 ◽  
Vol 67 (10) ◽  
pp. 1636-1643 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Mahmood Tajerbashi ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Physical Properties ◽  
Least Squares ◽  
Crystal Structures ◽  
Direct Methods ◽  
Structural Studies ◽  
Boron Compounds ◽  
Organoboron Compounds ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths

Details of the syntheses, physical properties, and crystal structures of the title compounds are reported. Crystals of 4-(N-methoxymethylimino)-2,2-diphenyl-1,3-dioxa-2-borata-1,2,3,4-tetrahydronaphthalene, 4, are monoclinic, a = 9.8072(5), b = 9.6217(7), c = 19.6793(12) Å, β = 94.871(5)°, Z = 4, space group P21/c, and those of 4-diethylimino-2,2-diphenyl-1,3-dioxa-2-borata-1,2,3,4-tetrahydronaphthalene, 9, are orthorhombic, a = 17.0593(7), b = 16.1372(6), c = 14.3753(5) Å, Z = 8, space group Pbca. Both structures were solved by direct methods and were refined by full-matrix least-squares procedures to R = 0.046 and 0.038 for 2198 and 2969 reflections with I ≥ 3σ(I), respectively. In both structures the N,N-dialkylsalicylamidate ligands coordinate the diphenylboron moieties via the phenolate oxygen and amide oxygen atoms, forming six-membered O—B—O chelate rings. The O(ar)—B, O(amide)—B, and mean C—B bond lengths (corrected for libration) are as follows: 1.490(3), 1.549(4), and 1.612 Å for 4 and 1.494(2), 1.550(2), and 1.612 Å for 9. Keywords: crystal structures, boron compounds, organoboron compounds.

Structural studies of organoboron compounds. XXVII. (3-Hydroxy-2-methyl-4-pyridinonato)diphenylboron and (3-hydroxy-1,2-dimethyl-4-pyridinonato)diphenylboron

1988 ◽  
Vol 66 (1) ◽  
pp. 132-138 ◽  
Author(s):  
William O. Nelson ◽  
Chris Orvig ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Least Squares ◽  
Crystal Structures ◽  
Direct Methods ◽  
Structural Data ◽  
Structural Studies ◽  
Organoboron Compounds ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths ◽  
Oxygen Atoms

Details of the preparation and crystal structures of the title compounds are given. Crystals of (3-hydroxy-2-methyl-4-pyridinonato)diphenylboron, 1, are orthorhombic, a = 13.4010(6), b = 15.005(1), c = 14.833(1) Å, Z = 8, space group Pbca, and those of (3-hydroxy-1,2-dimethyl-4-pyridinonato)diphenylboron, 2, are monoclinic, a = 8.2617(5), b = 12.374(1), c = 16.104(1) Å, β = 92.741(5)°, Z = 4, space group P21/n. Both structures were solved by direct methods and were refined by full-matrix least-squares procedures to R = 0.047 and 0.071 for 1654 and 1831 reflections with I ≥ 3σ(I), respectively. Both molecules contain five-membered C2O2B chelate rings, that in 2 being nearly planar. Structural data indicate weaker overall binding of the ligand oxygen atoms to boron in 1 than in 2. Bond lengths (corrected for libration) are O—B = 1.497(5) and 1.650(5), C—B = 1.600(5) and 1.599(5) Å for 1; O—B = 1.542(5) and 1.569(5), C—B = 1.607(6) and 1.609(6) Å for 2.

Structural studies of organoboron compounds. XXX. 1,9-Dimethyl-3,5,7-triphenyl-2,4,6,8-tetraoxa-1,9-diazonia-5-bora-3,7- diboratatricyclo[5.4.0.03,9]undecane

1988 ◽  
Vol 66 (5) ◽  
pp. 1117-1122 ◽  
Author(s):  
Henning Amt ◽  
Wolfgang Kliegel ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Physical Properties ◽  
Least Squares ◽  
Title Compound ◽  
Direct Methods ◽  
Ring System ◽  
Structural Studies ◽  
Organoboron Compounds ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths

Details of the preparation and physical properties of the title compound are given. Crystals of 1,9-dimethyl-3,5,7- triphenyl-2,4,6,8-tetraoxa-1,9-diazonia-5-bora-3,7-diboratatricyclo[5.4.0.03,9]undecane are orthorhombic, a = 9.4026(3), b = 9.4663(2), c = 24.7462(9) Å, Z = 4, space group P212121. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.036 and Rw = 0.038 for 1536 reflections with I ≥ 3σ(I). The three six-membered and two seven-membered rings comprising the tricyclo[5.4.0.03,9]undecane ring system all have boat or boat-like conformations. Important bond lengths (corrected for libration) are: B(sp3)—N = 1.649(6) and 1.668(6), B(sp3)—O(N) = 1.492(5) and 1.497(6), B(sp3)—O[B(sp2)] = 1.444(6) and 1.438(5), B(sp3)—C = 1.600(6) and 1.594(7), B(sp2)—O = 1.357(6) and 1.370(6), B(sp2)—C = 1.574(6) Å.

Structural studies of organoboron compounds. XX.(Salicylaldoximato-O,N)diphenylboron

1984 ◽  
Vol 62 (7) ◽  
pp. 1363-1368 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Hydrogen Bonds ◽  
Least Squares ◽  
Chelate Ring ◽  
Direct Methods ◽  
Structural Studies ◽  
Organoboron Compounds ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths ◽  
Phenolic Oxygen

Crystals of (salicylaldoximato-O,N)diphenylboron are triclinic, a = 10.125(2), b = 10.797(1), c = 14.760(2) Å, α = 89.05(1), β = 86.98(1), γ = 83.18(1)°, Z = 4, space group [Formula: see text]. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.040 and Rw = 0.048 for4145 reflections with I ≥ 3σ(I). The structure consists of two crystallographically independent, but essentially identical, molecules linked by strong [Formula: see text] hydrogen bonds to form continuous spirals along the a axis. The Ph2B moiety is chelated by the phenolic oxygen and oxime nitrogen atoms of the ligand resulting in the formation of a non-planar six-membered chelate ring. Important libration-corrected mean bond lengths are O—B = 1.516(1), N—B = 1.609(2), and C—B = 1.613(2) Å.

Structural studies of organoboron compounds. XXXIII. 4,4-Dimethyl-2,2-diphenyl-1,3-dioxa-4-azonia-2-boratacyclohexaneand 3,3-dimethyl-2-phenoxy-2-phenyl-1-oxa-3-azonia-2-boratacyclopentane

1989 ◽  
Vol 67 (5) ◽  
pp. 933-940 ◽  
Author(s):  
Eckardt Ebeling ◽  
Wolfgang Kliegel ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Physical Properties ◽  
Crystal Structures ◽  
Direct Methods ◽  
Molecular Structures ◽  
Structural Studies ◽  
Boron Compounds ◽  
Organoboron Compounds ◽  
Thermally Induced ◽  
Full Matrix ◽  
Space Group

Details of the syntheses, physical properties, and crystal structures of the title compounds are reported. Crystals of 4,4-dimethyl-2,2-diphenyl-1,3-dioxa-4-azonia-2-boratacyclohexane, 3, are monoclinic, a = 6.512(1), b = 15.765(2), c = 14.342(4) Å, β = 93.170(7)°, Z = 4, space group Pn, and those of 3,3-dimethyl-2-phenoxy-2-phenyl-1-oxa-3-azonia-2-boratacyclopentane, 4, are orthorhombic, a = 13.5829(8), b = 16.940(1), c = 6.3181(4) Å, Z = 4, space group P21212. Both structures were solved by direct methods and were refined by full-matrix least-squares procedures to R = 0.034 and 0.034 for 1974 and 1478 reflections with I ≥ 3σ(I), respectively. The molecular structures are discussed in terms of the thermally-induced 1,2-migration of B-substituents by which 3 is converted to 4. Keywords: crystal structures, boron compounds, organoboron compounds.

Structural studies of organoboron compounds. XLII. 4,6-Bis(1-cyano-1-methylethyl)-2-mesityl-1,3-dioxa-4,6-diaza-2-boracyclohexane

1991 ◽  
Vol 69 (2) ◽  
pp. 234-238 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Gottfried Lubkowitz ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Least Squares ◽  
Key Words ◽  
Good Yield ◽  
Direct Methods ◽  
Organoboron Compound ◽  
Structural Studies ◽  
Full Matrix ◽  
Bond Lengths

The condensation of N,N′-bis(1-cyano-1-methylethyl)-N,N′-dihydroxymethanediamine and mesitylboronic acid gives 4,6-bis(1-cyano-1-methylethyl)-2-mesityl-1,3-dioxa-4,6-diaza-2-boracyclohexane in good yield. Crystals of the latter compound are orthorhombic, a = 15.825(1), b = 17.958(1), c = 14.014(1) Ǻ, Z = 8, space group Pbca. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.037 and Rw = 0.051 for 2844 reflections with 1 ≥ 3σ(I). The molecule has a six-membered cycloboronate structure featuring the first structurally characterized BONCNO ring. The ring was found to have a C-envelope conformation in the solid state. Bond lengths include: O—B(sp2) = 1.356(2) and 1.370(2), and C(aryl)—B = 1.560(2) Ǻ. Key words: organoboron compound, boron compound, crystal structure.

Structural studies of organoboron compounds. XXIX. 6,6-Diethyl-2,2-diphenyl-1,3-dioxa-6-azonia-2-boratacyclooctane monohydrate

1988 ◽  
Vol 66 (5) ◽  
pp. 1091-1096 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Least Squares ◽  
Title Compound ◽  
Chelate Ring ◽  
Direct Methods ◽  
Structural Studies ◽  
Organoboron Compounds ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths ◽  
Conformation Intermediate

Details of the preparation and structure of the title compound are given. Crystals of 6,6-diethyl-2,2-diphenvl-1,3-dioxa-6-azonia-2-boratacyclooctane monohydrate are orthorhombic, a = 7.0322(2), b = 16.3505(7), c = 16.8164(4) Å, Z = 4, space group P212121. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.045 and Rw = 0.050 for 2013 reflections with I ≥ 3σ(I). The monocyclic eight-membered B, N-betaine is the first to be structurally characterized. The eight-membered chelate ring has a conformation intermediate between the S4 and boat-boat forms which is probably stabilized by transannular [Formula: see text] interactions. The average libration-corrected O—B and B—C bond lengths of 1.500 and 1.639 Å are, respectively, the shortest and longest yet observed for an O,O-chelate of diphenylboron.

Structural studies of organoboron compounds. XVI. Preparation and crystal and molecular structures of 4,4-dimethyl-2,5,5-triphenyl-1,3-dioxa-4-azonia-2-bora-5-boratacyclopentane and 4,4,5,5-tetramethyl-2,2-diphenyl-1,3-dioxa-4-azonia-2-boratacyclopentane

1984 ◽  
Vol 62 (5) ◽  
pp. 838-844 ◽  
Author(s):  
W. Kliegel ◽  
H.-W. Motzkus ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Physical Properties ◽  
Least Squares ◽  
Steric Hindrance ◽  
Direct Methods ◽  
Structural Features ◽  
Molecular Structures ◽  
Structural Studies ◽  
Full Matrix ◽  
Space Group ◽  
Crystal And Molecular Structures

Details of the synthesis, physical properties, and molecular structures of 4,4-dimethyl-2,5,5-triphenyl-1,3-dioxa-4-azonia-2-bora-5-boratacyclopentane, 4, and 4,4,5,5-tetramethyl-2,2-diphenyl-1,3-dioxa-4-azonia-2-boratacyclopentane, 5, are reported. Crystals of 4 are triclinic, a = 9.841(2), b = 14.722(3), c = 6.6701(12) Å, α = 86.79(1), β = 102.95(1), γ = 93.89(1)°, Z = 2, space group [Formula: see text]; and those of 5 are monoclinic, a = 14.9164(12), b = 6.4732(3), c = 18.2248(15) Å, β = 117.263(3)°, Z = 4, space group Cc. Both structures were solved by direct methods and were refined by full-matrix least-squares procedures to final R values of 0.032 and 0.035 for 1456 and 1649 observed reflections, respectively. Molecules of 4 contain non-planar BOBON rings with an unusually long N(sp3)—B(sp3) distance of 1.728(3) Å and in 5 there is a long N(sp3)—C(sp3) bond of 1.591(3) Å. These structural features are ascribed to steric hindrance.

Structural studies of organoboron compounds. XIX. 1,7-Dimethyl-3,5-diphenyl-2,4,6-trioxa-7-aza-1-azonia-3-bora-5-boratabicyclo[3.3.0]octane

1984 ◽  
Vol 62 (3) ◽  
pp. 515-520 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Solid State ◽  
Least Squares ◽  
Variable Temperature ◽  
Direct Methods ◽  
Structural Studies ◽  
Organoboron Compounds ◽  
Full Matrix ◽  
Space Group ◽  
H Nmr ◽  
Valence Tautomers

Crystals of 1,7-dimethyl-3,5-diphenyl-2,4,6-trioxa-7-aza-1-azonia-3-bora-5-boratabicyclo[3.3.0]octane are triclinic, a = 10.559(2), b = 15.156(3), c = 10.338(2) Å, α = 99.14(1), β = 89.90(1), γ = 96.73(1)°, Z = 4, space group [Formula: see text]. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to R = 0.032 and Rw = 0.038 for 2396 reflections with I ≥ 3σ(I). The structure consists of two crystallographically independent, but virtually identical, molecules containing sterically lengthened N—B coordinative bonds (mean 1.740(3) Å). The structurally inequivalent (in the solid state) pairs of N-methyl and B-phenyl groups are observed by variable temperature 1H nmr to be magnetically equivalent in solution, implying a rapid interconversion of "valence tautomers" at temperatures down to −60 °C.

Structural studies of organoboron compounds. XXXIX.1 1,4-Bis(2,2-diethoxyethyl)-6,8-diphenyl-5,7,9-trioxa-4-aza-1-azonia-8- bora-6-boratabicyclo[4.3.0]nonane

1990 ◽  
Vol 68 (10) ◽  
pp. 1791-1796 ◽  
Author(s):  
Henning Amt ◽  
Wolfgang Kliegel ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Title Compound ◽  
Phenylboronic Acid ◽  
Direct Methods ◽  
Organoboron Compound ◽  
Structural Studies ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths

Reaction of N,N′-1,2-ethanediylidenebis(2,2-diethoxyethanamine)- N,N′-dioxide and phenylboronic acid yields the title compound. Crystals of 1,4-bis(2,2-diethoxyethyl)-6,8-diphenyl-5,7,9-trioxa-4-aza-1-azonia-8-bora-6-boratabicyclo[4.3.0]-nonane are triclinic, a = 12.625(2), b = 13.962(2), c = 9.273(1) Å, α = 104.81(1), β = 98.61(1), γ = 106.52(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 R = 0.058 and Rw = 0.081 for 3677 reflections with I ≥ 3σ(I). The molecule has a bicyclo[4.3.0]nonane structure containing one transannular N—B bond. Important bond lengths are sp3-bomn, N—B = 1.759(3), O—B = 1.435(3) and 1.454(3), C—B = 1.579(4); sp2-boron, O—B = 1.335(3) and 1.404(3), C—B = 1.557(4) Å. The (sp3)B—C(phenyl) bond is the shortest yet reported for this type of compound.Keywords: crystal structure, boron compound, organoboron compound.

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