Borate tris hydro

Ligand abbreviations (6-Mepy)(py)2tren and (6-Mepy)2(py)tren = tris[4-[(6-/ )-2-pyridyl]-3-aza-6-butenyl]amme, R = H or CH3 HB(pz)3 = hydro-tris(pyrazolyl)borate paptH = 2-(2-pyridylamino)-4-(2-pyridyl)thiazole phenmethoxa = 3-[2-(l,10-phenanthrolyl)]-5-methyl-l,2,4-oxadiazole pyimH = 2-(2 -pyridyl)itnidazole pybimH = 2-(2 -pyridyl)benzimidazole ppa = JV -(2-pyridylmethyl)picolineamidine tpmbn = tetrakis(2-pyridylmcthyl)-meso-2,3-butane-diamine tppn = tetrakis-(2-pyridylmethyl)-l-methyl-l,2-propanediainine tpchxn = tetrakis(2-pyridylmethyl)-tra s-l,2-cyclohexanediamine biz = 2,2 -bi-1,4,5,6-tetrahydropyrimidine. 

Methyl-2-mercaptoimidazole Hydro tris (pyrazolyl)borate Substituted tris(pyrazolyl)borate Hydrotris(3,5-dimethylpyrazolyl)borate Triphenylphosphine-3,3, 3"-trisulfonate... 

Many /x-oxo dimers are not stable under reducing conditions owing to instability of the n-oxo bridge moiety in either the mixed-valence or diferrous states. For example, [Fe(HBpz3)]20(0Ac)2 (HBpz3 is hydro-tris(pyrazolyl)borate) shows an electrochemical irreversible reduction wave even at very high scan rates (5 V/s) (13). The fact that the ascorbic acid does not show the same reactivity as 2-mercaptoethanol may be a consequence of differences in the redox potentials or the ability of the reductant to displace ligands and coordinate to the metal center. 

Some of the first catalytic model systems for the simulation of the function of methane monooxygenase comprise monomeric as well as dimeric iron-containing model complexes bearing hydro-tris(pyrazolyl)borate ligands [6]. These complexes, e.g. 3, catalyze the oxidation of aromatic and aliphatic carbon-hydrogen bonds in the presence of oxygen (1 atm), acetic acid and zinc powder at room temperature (Scheme 2). 

Methyl derivatives of monocyclopentadienyl hydro-tris(pyrazolyl)borate uranium complexes CpUCl2 JVlexL (L = HB(3,5-Me2pz)3, x=, 2) were prepared by the reaction of CpUCl2L with appropriate amounts of MeLi in toluene (Scheme 22). 

A mononuclear zinc hydroxide complex supported by a hydrophobic hydro-tris(pyrazolyl)borate ligand mediates the stoichiometric hydrolysis of an activated amide.94 As shown in Scheme 17, treatment of [(TpCum,Me)Zn-OH] with... 

Model studies for metallo- 3-lactamases have been performed using mononuclear zinc hydroxide complexes.99,129,130 The breadth of (3-lactam hydrolysis reactivity of hydro-tris(pyrazolyl)borate-ligated mononuclear zinc hydroxide complexes has been explored.129 Treatment of the mononuclear zinc hydroxide complex [(Tpph Mc)Zn OH] with simple 3-lactams ( 3-propiolactam, 4-phenyl-(3-propiolactam, Scheme 21) does not result in ring opening, but instead results in the formation of 3-lactamide complexes and water. Treatment of [(Tpph,Me)Zn-OH] with /V-alkyl or -aryl 3-lactam derivatives instead results in no reaction (Scheme 21). Use of natural derivatives of penicillin and cephalosporin (Scheme 22) did not yield 3-lactam hydrolysis, but instead coordination of the carboxylate moiety of the antibiotic derivatives to the mononuclear Zn(II) center and release of water. 

The hydro-tris[3-(4-pyridyl)pyrazol-l-yl]borate, (Tp4py), has been isolated as its T1(I) complex which shows an infinite one-dimensional polymeric chain, in which the T1(I) center is connected to a pendant... 

An MOCVD route to barium borate thin films from a barium hydro-tri(l-pyrazolyl)borate single-source precursor... 

In order to introduce lipophilic character into technetium complexes that might be potentially suitable as " Tc radiopharmaceuticals, the hydro-tris(l-pyrazolyl)borate anion (HBpz.3 ) was used as a ligand. Dichloro hydro-lris(Tpyra7olyl)borato)oxotcch-... 

N,N -bi s(2-hydroxy benzyl)-1,3-diaminopropane 2 -hydroxybenzylidine-2-hydroxyaniline hydro-tris(l -pyrazolyl)borate... 

T2 Ai crossover has also been reported in a ferrous complex with the chelating ligand hydro-tris-(l-pyrazolyl)borate [11, 12]. The geometry of the... 

Fig. 8.3 The structure of hydro-tris-(l-pyrazolyl)borate chelate. [Ref. 11, Fig. 1]...

The previously unreported complex, Tp Zn(K -BH4) (Tp =hydro-tris(3,5-dimethylpyrazolyl)-borate anion), has been characterized by Des-rochers et al. by the use of IR and NMR spectroscopies including measurements of Vhb couplings which allowed the authors to compare it with analogous closed shell borohydride complexes. All measurements have confirmed the persistent but fluxional zinc-borohydride coordination in solution on the NMR timescale. The 1 1 1 1 quartet assigned to coordinated borohydride in the proton spectrum (Vhb = 83Hz) has confirmed the equivalence of all hydrogen atoms because of rapid interconversion of the protons coordinated and not coordinated to the metal. 

Since its preparation, reactions of RuCl[k -HB(pz)3](PPh3)2 have been investigated in a number of papers. The lability of both the phosphines and the chloride hgand allow functional group transformations to be carried out in order to provide a wide range of ruthenium hydro-tris(pyrazol-l-yl)borate complexes. A straightforward preparation of the complex on a large scale (10 g) is described here. 

N5BHKC15H21, Borate(l-), tris(3,5-dimethyl-pyrazolyl)hydro-, potassium, 33 220 N5BHKS3C12H15, Borate(l-), hydrotris(methi-mazolyl)-, potassium, 33 200 N5BM0O3C17H26, Molybdenium(V), hydro-tris(3,5-dimethyl- l-pyrazolyl)borato-,... 

Boron is determined by oxidation of tri(sec-butyl)borane to 2-butanol.911,12 A 4.0-mL aliquot of the potassium tri(sec-butyl)hydro-borate(l — ) solution is hydrolyzed by adding it, with stirring, to a mixture of... 

Several ZrLCl2(OR) complexes (R = alkyl or aryl) that contain the Tripodal Ligand tris(3,5-dimethylpyrazolyl)hydro-borate, HBpzj, which is considered a formal isolobal analog of cyclopentadienide, have been obtained. In all of them the metal atom is six-coordinate, as in CpZrCl2(OR) complexes. ... 

BCuN6OCioH10, Copper , car-bonyl[hydrotris(pyrazolato)borato]-, 21 108 BCuN6OCi6H22, Copper , carbonyl[tris(3,5-dimethylpyrazolato)hydroborato]-, 21 109 BCuNsOCisHn, Copper , car-bonyl[tetrakis(pyrazolato)borato]-, 21 110 BNNaC2H3, Borate 1 -), cyanotri[(2//)hydro)-, sodium, 21 167... 

BN RhC44HM, Rhodium , tetrakis(l-isocy-anobutane)-, tetraphenylborate(l -), 21 50 BN C Hio, Borate(l -), hydrotris(pyrazolato)-, copper complex, 21 108 BN6Ci5H22, Borate(l -), tris(3,5-dimethylpyr-azolato)hydro-, copper complex, 21 109 BN8Ci2Hi2, Borate(l-), tetrakis(pyrazolato)-, copper complex, 21 110 BjFeN CjoH,, Iron(II), [tris[p.-[(l,2-cy-clohexanedione dioximato)-0 0 ]diphenyl-diborato(2 — )]-NJI JI" X " JI"",... 

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