ChemInform Abstract: SYNTHESIS OF A BORON CHELATE OF 1-METHYL-4,5,6,7-TETRAHYDROINDIGO

1978 ◽  
Vol 9 (52) ◽  
Author(s):  
G. PFEIFFER ◽  
H. BAUER
Keyword(s):  
Boron Chelate

Synthesis of C-aryl-N-(2-hydroxyphenylmethyl)-nitrones and their reaction with diphenylborinic or carboxylic acid derivatives. Crystal and molecular structures of a free nitrone ligand and its diphenyl–boron chelate

1997 ◽  
Vol 75 (12) ◽  
pp. 1830-1843 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Jörg Metge ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Carboxylic Acid ◽  
Electron Distribution ◽  
Direct Methods ◽  
Molecular Structures ◽  
State Structure ◽  
Space Group ◽  
Crystal And Molecular Structures ◽  
New Type ◽  
Boron Chelate ◽  
Diphenylboron Chelate

The syntheses of a number of aromatic aldonitrones of N-(2-hydroxyphenylmethyl)hydroxylamine and their subsequent reactions with diphenylborinic or carboxylic acid derivatives are reported. Crystals of 8-(4-dimethylaminophenylmethylene)-6,6-diphenyl-5,7-dioxa-8-azonia-6-borata-5H-6,7,8,9-tetrahydrobenzocycloheptene, 2b, are triclinic, a = 10.6802(8), b = 11.1809(4), c =10.1520(3) Å, α = 105.847(3)°, β = 92.567(4)°, γ = 84.610(5)°, Z = 2, space group PĪ, and those of C-(4-dimethylaminophenyl)-N-(2-hydroxyphenylmethyl)nitrone, 6e, are monoclinic, a = 12.2319(8), b = 7.071(1), c = 17.2005(9) Å, β = 107.520(4)°, Z = 4, space group P21/a. The structures were solved by direct methods and refined by full-matrix least-squares procedures to R = 0.035 and 0.032 (Rw = 0.036 and 0.032) for 3379 and 1800 reflections with I ≥ 3σ(I), respectively. Compound 2b is representative of a new type of heterocyclic B,N-betaine. The solid state structure of 6e (the precursor to 2b) shows that only small topological changes, but significant changes in the electron distribution, occur upon the formation of the diphenylboron chelate. Keywords: aromatic aldonitrones, organoboron compounds, crystal structures.

C-(2-Hydroxyaryl)-N-(2-hydroxyphenylmethyl)nitrones as regioselective bidentate ligands in boron chelate formation. Crystal and molecular structures of a diphenylboron complex and its parent ligand

1998 ◽  
Vol 76 (7) ◽  
pp. 1082-1092 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Jörg Metge ◽  
Steven J Rettig ◽  
James Trotter
Keyword(s):  
Direct Methods ◽  
Acid Anhydride ◽  
Molecular Structures ◽  
Bidentate Ligands ◽  
Full Matrix ◽  
Space Group ◽  
Crystal And Molecular Structures ◽  
Chelate Formation ◽  
Boron Chelate ◽  
Parent Ligand

The C-(2-hydroxyaryl)-N-(2-hydroxyphenylmethyl)nitrones 5 are synthesized by the condensation of variously substituted salicylaldehydes with N-(2-hydroxyphenylmethyl)-hydroxylamine. These nitrones react with diphenylborinic acid anhydride to form seven-membered diphenylboron chelates 6. Crystals of C-(4-diethylamino-2-hydroxyphenyl)-N-(2-hydroxyphenylmethyl)nitrone, 5d, are monoclinic, a = 6.911(2), b = 10.663(2), c = 22.951(1) Å, β = 97.33(1)°, Z = 4, space group P21/n, and those of 4-dimethylamino-8-(2-hydroxyphenylmethyl)-6,6-diphenyl-5,7-dioxa-8-azonia-6-borata-6,7-dihydro-5H-benzocycloheptene-ethanol, 6d·EtOH, are monoclinic, a = 9.069(2), b = 29.881(1), c = 11.1883(6) Å, β = 109.426(9)°, Z = 4, space group P21/n. The structures were solved by direct methods and refined by full-matrix least-squares procedures to R = 0.032 and 0.039 (R w = 0.031 and 0.036) for 2510 and 4162 reflections with I > 3σ(I), respectively. Key words : C-(2-hydroxyaryl)-N-(2-hydroxyphenylmethyl)nitrones, organoboron compounds, crystal structures.

ChemInform Abstract: Vinamidine Boron Chelate Compounds.

ChemInform ◽  
1990 ◽  
Vol 21 (34) ◽  
Author(s):  
N. KUHN ◽  
A. KUHN ◽  
M. SPEIS ◽  
D. BLAESER ◽  
R. BOESE
Keyword(s):  
Chelate Compounds ◽  
Boron Chelate

Massenspektrometrische Untersuchungen an Borchelaten der Pyridin- und Chinolin-Reihe und deren N-Oxiden / Mass Spectrometric Investigations on Boron Chelates of the Pyridine and Quinoline Type and their N-Oxides

1973 ◽  
Vol 28 (7-8) ◽  
pp. 440-445 ◽  
Author(s):  
Eberhard Hohaus ◽  
Wolfgang Riepe
Keyword(s):  
Carboxylic Acid ◽  
Mass Spectra ◽  
Membered Ring ◽  
Mass Spectrometric ◽  
Ring Closure ◽  
Boron Chelates ◽  
Boron Chelate

Mass spectra of chelate-6-rings (N-oxide-chelates) are similar to those of comparable chelate-5-rings after elimination of oxygen from the fragment ion (M-C6H5). It is assumed that the fragment ion [(M-C6H5)-O] exists as a five-membered ring.However, there are two exceptions which are: The diphenyl boron chelate of pyridine-2-carboxylic acid anilide N-oxide with O-B-O-coordination and the difluorine boron chelate of 8-hydroxyquinoline N-oxide. The stable fragment OBX (X = C6H5F) is eliminated directly from the fragment ion (M-X). It is assumed the ring closure in [(M-X)-O] obviously is less favoured. The preparation of both 5-ring-chelates using the components is impossible, too.

Redox-active, near-infrared dyes based on ‘Nindigo’ (indigo-N,N′-diarylimine) boron chelate complexes

2013 ◽  
Vol 4 (2) ◽  
pp. 612-621 ◽  
Author(s):  
Graeme Nawn ◽  
Simon R. Oakley ◽  
Marek B. Majewski ◽  
Robert McDonald ◽  
Brian O. Patrick ◽  
...  
Keyword(s):  
Near Infrared ◽  
Chelate Complexes ◽  
Redox Active ◽  
Boron Chelate Complexes ◽  
Boron Chelate
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