Convenient synthesis, separation, and x-ray crystal structure determinations of 1(e),3(e),5(e)-trimethylcycloborazane and 1(e),3(e),5(a)-trimethylcycloborazane

1986 ◽  
Vol 25 (19) ◽  
pp. 3346-3349 ◽  
Author(s):  
Chaitanya K. Narula ◽  
Jerzy F. Janik ◽  
Eileen N. Duesler ◽  
Robert T. Paine ◽  
Riley Schaeffer
1993 ◽  
Vol 48 (6) ◽  
pp. 785-793 ◽  
Author(s):  
Hans-Friedrich Klein ◽  
Michael Helwig ◽  
Michael Karnop ◽  
Herbert König ◽  
Birgit Hammerschmitt ◽  
...  

Mononuclear cobalt(0) complexes Co(η2-azaolefin)(PMe3)3 (azaolefin = benzo[c]cinnoline (1), p-dimethylamino-phenyl(phenyl)diazene (2), 1/2 diazobenzene (3), bis(p-tolyl)diazene (4), bis(p-fluorphenyl)diazene (5), bis(p-trifluoromethyl-phenyl)diazene (6), phenylisocyanate (7)) are obtained from Co(cyclo-C5H8)(PMe3)3 by substitution of the olefin. X-ray crystal structure determinations of 1 and 7 show tetrahedral arrangements of ligands around the cobalt atom. By reaction with carbon monoxide carbonyl(phosphine)cobalt(0) complexes are formed. 7 catalyses the cyclotrimerization of phenylisocyanate, while with CoCl(PMe3)3 as a catalyst the cyclic dimer of phenylisocyanate is selectively formed. A convenient synthesis for CoCl(PMe3)3 is described.


Author(s):  
Moisés Canle L. ◽  
William Clegg ◽  
Ibrahim Demirtas ◽  
Mark R. J. Elsegood ◽  
Howard Maskill

1988 ◽  
Vol 43 (10) ◽  
pp. 1279-1284 ◽  
Author(s):  
Mervat El Essawi ◽  
H Gosmann ◽  
D Fenske ◽  
F Schmock ◽  
K Dehnicke

Triphenylmethylphosphonium nitrite and formate have been prepared by the reaction of [PPh3Me]I with silver nitrite, and lead formate, respectively, in aqueous solutions. [PPh3Me]NO2 (1) forms pale yellow crystals, and [PPh3Me]HCO2·H2O (2) forms white crystals. Both compounds are soluble in water, ethanol, and dichloromethane. In moist air 2 is hydrated to yield [PPh3Me]HCO2·2H2O (3). The compounds were characterized by their IR spectra, 1 and 2 also by X-ray crystal structure determinations.[PPh3Me]NO2 (1): space group P21/n, Z = 4, 2088 independent observed reflexions, R = 0.062. Lattice dimensions (20 °C): a = 914.7(3), b = 1887.5(9), c = 1080.0(4) pm, β = 110.29(3)°. The compound consists of PPh3Me+ ions and NO2- anions with bond lengths of 114.2(6) pm and a bond angle of 124.1(7)°. [PPh3Me]HCO2·H2O (2): space group P21/n, Z = 4, 2973 independent observed reflexions, R = 0.069. Lattice dimensions (-20 °C): a = 931(2), b = 1558(3), c = 1281(2) pm, β = 105.9(1)°. The compound consists of PPh3Me+ ions and formate anions which form centrosymmetric dimeric units [HCO2·H2O]22- through hydrogen bridges of the water molecules. Bond lengths CO 122.4(4) and 120.9(4) pm. bond angle OCO 129.9(4)°.


1988 ◽  
Vol 43 (10) ◽  
pp. 1256-1262 ◽  
Author(s):  
Hans-Friedrich Klein ◽  
Goetz Lull ◽  
Birgit Rodenhäuser ◽  
Gerhard Cordier ◽  
Helmut Paulus

Mononuclear cobalt(o) complexes containing olefin and trimethylphosphane ligands Co(olefin)(PMe3)3 (olefin = C2H4 (1), C3H6 (2), cyclopentene (3), trans-1,2-diphenylethene (4), tetrafluorobenzo-bicyclo-(2.2.2)-octadiene (5)), are obtained from CoCl2 by reaction with magnesium in the presence of the ligands or by substitution of 3 with olefin. X-ray crystal structure determinations of 4 and 5 show a distorted tetrahedral arrangement of ligands around the cobalt atom. Chemical and spectroscopic properties are consistent with a paramagnetic valence state of the compounds in solution. By reaction with carbon monoxide a dicobalt complex is formed, while azobenzene gives paramagnetic Co(N2Ph2)(PMe3)2.


1985 ◽  
Vol 38 (4) ◽  
pp. 575 ◽  
Author(s):  
MP Hartshorn ◽  
WT Robinson ◽  
J Vaughan ◽  
JM White

Nitration of the bromophenols (4a) and (5a) give products of nitro-debromination . Reaction of 6-methyl-4-nitro-2-phenylphenol (5c) with nitrogen dioxide gives 2-hydroxy-2-phenylcyclohex-3-enones (8) and (9), and probably stereoisomers (10), (20), (21) and (22). The mode of ormation of these compounds is discussed. X-ray crystal structure determinations are reported for compounds (8) and (9).


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