Synthesis and crystal and molecular structure of ethanolaminogallium dimethyl, H 2 NCH 2 CH 2 O•GaMe 2

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Section: 094(7)mentioning

confidence: 52%

Synthesis and structure of 3,5-dimethylpyrazolyl iron and cobalt dinitrosyl dimers

Chong¹,

Rettig²,

Storr³

et al. 1979

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“…In this regard the complex is similar to the ethanolamine dimethylgallium complex, H2NCH2CH20. GaMe2, which also exists in the solid state as discrete monomers linked by an extensive network of N-Ha .O hydrogen bonds (13). The five-coordinate dimeric structures of the methylated analogs [Me2NCH2CH2O.GaR2I2 (R = Me, H) (14) support the contention that extensive hydrogen bonding involving ligand atoms in compounds of this type is energetically more favorable than the formation of oligomers involving weak Ga-0 interactions.…”

Section: Resultsmentioning

confidence: 90%

Synthesis and structural characterization of glycinatodimethylgallium, (C₂H₄NO₂)Ga(CH₃)₂

Rettig¹,

Storr²,

Trotter³

1987

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. Can. J. Chem. 65, 1349Chem. 65, (1987. Details of the preparation and crystal structure of the title compound are given. Crystals of glycinatodimethylgallium are monoclinic, a = 12.502(1), b = 12.023(1), c = 10.732(1) A, P = 110.05(1)", Z = 8, space group P 2 1 / c . The structure was solved by conventional heavy atom methods and was refined by full-matrix least-squares procedures to R = 0.033 and R,,, = 0.039 for 1172 reflections with I ? 3u(I). The structure consists of monomeric (C2H4N02)GaMe2 molecules which are linked together by an extensive network of N-H...O hydrogen bonds. The Ga atoms have tetrahedral coordination geometry with bond lengths averaged over the two crystallographically independent molecules: Ga-0 = 1.958(18), Ga-N = 2.031(5), and Ga-C = 1.937(7) A. IntroductionThe importance of a-amino acids as the principal constituents of protein and living matter is unquestionable. One such protein, transferrin (a glycoprotein of molecular weight -80 OOO), is responsible for iron transport in mammalian systems and has been implicated in the transport of gallium in vivo (1, 2).Recently we have been interested in the area of gallium citrate chemistry (3), primarily since gallium citrate complexes are important clinical agents in medicinal chemistry (1) and definitive structural data on such complexes was entirely lacking. Our attention has also focussed on the coordination chemistry of gallium species with simple a-amino acids with a view to elucidating the binding of gallium by such compounds. The present paper details the preparation and structural characterization of the glycinatodimethylgallium complex. ExperimentalAir-sensitive materials were handled under oxygen-free dry nitrogen or on a high-vacuum line. Benzene was dried by refluxing over molten potassium followed by distillation under an atmosphere of nitrogen. Starting materialsTrimethylgallium was synthesized from gallium metal and dimethylmercury as described previously (4). Glycine (Eastman Organic Chemicals) was used as supplied. Synthesis of glycinatodimethylgalliumMe3Ga (1.325 g, 11.55 mmol) was condensed onto glycine (0.866 g, 11.55 mmol) at -196OC. Alternate warming and cooling resulted in a vigorous reaction well below room temperature, with evolution of methane:Yield 70%. Anal. calcd. for (C2H4N02)GaMe2: C 27.60, H 5.76, N 8.06; found: C 27.69, H 5.83, N 7.93. Mass spectrumThe mass spectrum displayed as its highest m/e signal one due to the monomer -Me' ion. In addition signals from ions arising from the expected fragmentation of the monomer species were also observed. X-ray crystallographic analysisCrystals were sealed under dry nitrogen in glass capillaries. A crystal bounded by the eight faces (followed by the distances in mm between (extended by 25% on both sides for background measurement) was employed. Data were measured to 20 = 50". The intensities of three check reflections, measured every 3600 s throughout the data collection, decreased uniformly by 18.5%, the data being scaled accordingly. After data reduction,' an abso...

“…Polyfunctional ligands derived from hydrazine (1 -3), pyrazole (4)(5)(6)(7)(8), pyridazine (4, 9-1 I), and phthalazine (4,9,11,(12)(13)(14)(15)(16)(17)(18)(19) form transition metal complexes in which the metals are brought into close proximity because of the presence of the N,, diazine, fragments in these systems. Antiferromagnetic exchange between the adjacent metal centres has been demonstrated in some of these complexes (4,11,13,15,16,18) and catecholase activity has been shown with binuclear copper complexes of the binucleating ligand 1,4-di(2'-pyridyl) aminophthal- 'To whom all correspondence should be addressed.…”

Section: Introductionmentioning

confidence: 99%

Copper complexes of polyfunctional phthalazines. Mononuclear and polynuclear derivatives

Bautista¹,

Dewan²,

Thompson³

1982

. Can. J. Chem. 60,2583Chem. 60, (1982. Mononuclear, binuclear, and trinuclear copper(I1) complexes of the tetradentate ligands 1,4-di(2'-pyridyl) aminophthalazine (PAP) and 1,4-di(4'-methyl-2'-pyridyl) aminophthalazine (PAP4Me) and binuclear complexes of the tetradentate ligand 1,4-di(6'-methyl-2'-pyridyl) aminophthalazine (PAP6Me) are reported. In a series of binuclear carboxylate derivatives carboxylate bridges exist between copper centres in all cases and in some cases oxygen bridges (hydroxide or methoxide) are indicated. In all other polynuclearderivatives hydroxide bridges are anticipated on the basis of analytical, spectral, and magnetic data. The ligandsexist as anionic groups in some binuclear carboxylate derivatives while in the other polynuclear systems neutral ligands are found. In reactions in aqueous solution protonated mononuclear derivatives are obtained for both PAP and PAP4Me in cases where solutions of the metal salts are inherently acidic, followed by polynuclear, neutral ligand complexes which form when the pH increases. On a prepare les complexes mono-, bi-et trinuclkaires du cuivre(I1) des ligands tetradentates di(pyridy1 2')-1,4 aminophtalazine (PAP) et di-(methyl-4' pyridyl-2')-1,4 aminophtalazine (PAP4Me) et les complexes binuclkaires du ligand tetradentate di(methy1-6' pyridyl-2')-1,4 aminophtalazine (PAP6Me). Dans une sCrie de derives carboxylates binucltaires, il existe dans tous les cas des ponts carboxylates entre les centres cuivre et, dans certains cas, on trouve des ponts oxygknes (hydroxyde ou methylate). En se basant sur des donnees analytiques, spectrales et magnetiques, on prkvoit qu'il existera des ponts hydroxydes dans tous les autres derivks polynucleaires. Les ligands existent sous forme de groupes anioniques dans certains carboxylates binucleaires tandis que, dans d'autres systkmes polynuclkaires, on trouve des ligands neutres. Lorsque les solutions de sels mCtalliques sont intrinsequement acides, on obtient des derives mononuclCaires protones avec le PAP et le PAP4Me en solution aqueuses e t des complexes polynucleaires de ligands neutres lorsque le pH augmente. On n'obtient pas de complexes mononucleaires protones avec le PAP6Me alors que des facteurs stCriques empechent la formation de tels derives. On a observe de faibles moments magnetiques ( 1.1-1.5 BM) pour la plupart des complexes ayant un pont hydroxyde tandis qu'on observe des valeurs plus faibles (< 0.70 BM) pour deux complexes binucleaires du PAP6Me; ceci indique qu'il existe une possibilitk d'un fort echange antiferromagnetique entre les centres mCtalliques. Une etude preliminaire du complexe [CU,(PAP~M~)(OH)(NO,)~(H~O)~]NO, par cristallographie de rayons X indique une structure binuclkaire triplement pontCe incluant un pont nitrate bidentate et un pont hydroxyde avec un angle du pont oxygkne de 115,2".[Traduit par le journal]