Dihydrobis borate

Complexes of the titanium and vanadium groups are searee but mainly follow the routine eoordination modes. Sometimes for the dihydrobis(pyrazol-l-yl) borates, the role of M - - - H—B agostie interaetions is signifieant. 

From dihydrobis(l-imidazolyl)borate or tetrakis(l-imidazolyl)borate and silver salts the interesting mixed tetrametallic macrocycles 24 and 25 (Fig. 8) are prepared in high yields (40-60%) [36]. 

Bardwell, D. A. Jeffery, J. C. Jones, P. L. McCleverty, J. A. Psillakis, E. Reeves, Z. R. Ward, M. D. Lanthanide complexes of the tetradentate N-donor ligand dihydrobis[3-(2-pyridyl)pyrazolyl]borate and the terdentate N-donor ligand 2,6-bis(lH-pyrazol-3-yl)pyridine syntheses, crystal structures and solution structures based on luminescence lifetime studies. J. Chem. Soc., Dalton Trans. 1997, 2079-2086. 

Potassium dihydrobis(l-pyrazolyl)borate, m.p. 171-172°C., is a white crystalline solid, highly soluble in water and polar solvents. It may be recrystallized from anisole, but with large solubility losses. The infrared spectrum has a complicated BH2 stretch multiplet in the 2200-2500-cm.-1 range. It is very soluble in water and alcohols, but the ligand undergoes slow solvolysis, and solutions should be made up just before use. 

D. BIS[DIHYDROBIS(l-PYRAZOLYL)BORATO]NICKEL(II)— TRANSITION-METAL POLY (l-PYRAZOLYL)BORATES... 

Potassium dihydrobis(l-pyrazolyl)borate (18.6 g., 0.1 mole) of the solid as prepared in Sec. A is stirred in 300 ml. of distilled water, and any insolubles are removed by filtration. To the resulting clear solution is added, with stirring, 100 ml. of 0.5 M solution of nickel(II) acetate [or any other Ni(II) salt]. A yellowish precipitate forms immediately. The mixture is stirred at room temperature for 10 minutes and is then filtered. The solid is washed with copious amounts of water, then with... 

Pyrazaboles substituted on either the ring or the boron may be obtained by reaction between the appropriately substituted pyrazole and the appropriately substituted borane.11 For example the 2,6-dibromo-4,4,8,8-tetraethylpyrazabole can be made by the reaction between 4-bromopyrazole and pyrophoric triethylborane in xylene at reflux temperature. Another route to such compounds involves the dihydrobis(l-pyrazolyl)borate... 

Dihydrobis (pyrazolyl )borate Dihydrobis (3,5-dim ethylpy razolyl )borate Cholecystokinin Cyclohexanedionedioxime Central nervous system 2-(Diphenylphosphanyl)benzoic acid 2,3-Diaminopropionic acid Electrospray ionization mass spectrometry Fourier transform IR Gastrin-releasing peptide... 

X-ray crystal structure of the potassium dihydrobis(3-nitro-l,2,4-triazolyl) borate is reported [170], The potassium salt is polymeric and shows several K...N and K...0 interactions. 

Lanthanide complexes with dihydrobis(benzimidazolyl)borate for which a seven-coordinate polymeric structure was proposed have been described by Khan and co-workers.171... 

The ligand dihydrobis(3,4,5-tribromopyrazol-l-yl)borate, (BpBr3), and its derivative [Mo(BpBr3)(t 3-methallyl)(CO)2] have been prepared and characterized by Trofimenko and coworkers who compared the structure of the Mo complex with that of [Mo(Bp )(t 3-methallyl) (C O) 2 ].152... 

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