Binuclear copper complexes: an open and shut case. A strong antiferromagnetically coupled .mu.-monohydroxo bridged complex

Burk, Patrick L.; Osborn, John A.; Youinou, Marie‐Thérèse; Agnus, Yvette; Louis, R.; Weiss, Raymond

doi:10.1021/ja00395a072

Cited by 76 publications

(28 citation statements)

References 2 publications

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“…Magnetic measurements on protein extracts indicate strong antiferromagnetic exchange between the copper-(11) centres in Rhus vernicifera laccase (-25 2 1000 cm-I) (36) and in oxyhemocyanin (Megathura crenulata; -2J 2 1250 cm-I) (37). Strong antiferromagnetic exchange is observed in binuclear copper systems involving single hydroxy bridges (29,35,38) and exchange increases with bridge angle (29,34). An oxygen bridge from, e.g., tyrosine has been suggested as a super-exchange medium for both oxyhemocyanin (39) and enzymes containing Type I11 copper centres (35,38) and other donor groups around the copper centres are thought to include histidine (38).…”

Section: Fig 2 Proposed Structures For V (Xmentioning

confidence: 99%

“…Strong antiferromagnetic exchange is observed in binuclear copper systems involving single hydroxy bridges (29,35,38) and exchange increases with bridge angle (29,34). An oxygen bridge from, e.g., tyrosine has been suggested as a super-exchange medium for both oxyhemocyanin (39) and enzymes containing Type I11 copper centres (35,38) and other donor groups around the copper centres are thought to include histidine (38). With these properties in mind we see our complexes as potential models for such centres and are embarked on a program to investigate detailed magnetic and structural characteristics of some of our systems.…”

Section: Fig 2 Proposed Structures For V (Xmentioning

confidence: 99%

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Copper complexes of polyfunctional phthalazines. Mononuclear and polynuclear derivatives

Bautista¹,

Dewan²,

Thompson³

1982

Can. J. Chem.

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. 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]

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Section: Fig 2 Proposed Structures For V (Xmentioning

confidence: 99%

Section: Fig 2 Proposed Structures For V (Xmentioning

confidence: 99%

Copper complexes of polyfunctional phthalazines. Mononuclear and polynuclear derivatives

Bautista¹,

Dewan²,

Thompson³

1982

Can. J. Chem.

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“…Recent reports of binuclear copper complexes involving just single hydroxy bridges have included nitrogen-containing Iigands with much more flexibility than the pyridylphthalazines, and which do not have binucleating fragments, like the diazine nitrogen pair, situated together (8,9). Oxygen bridge angles, metal-metal separations and hence exchange integrals are somewhat larger in these systems.…”

Section: [Cu~(pap~m~)(oh)(h~o)~(no~)~]no~ Are Also Included Formentioning

confidence: 99%

“…Magnetic measurements on protein extracts indicate strong antiferromagnetic exchange between the copper(I1) centres in Rhus vernicifera laccase (5) (-2J > 1000 cm-') and in oxyhemocyanin (Megathura crenulata; -2 J > 1250 cm-') (5,6). Strong antiferromagnetic exchange is observed in binuclear copper(I1) systems involving single hydroxy bridges (7)(8)(9) and exchange increases with increasing bridge angle (7). In systems of this sort the copper- (11) centres are assumed to be superexchange coupled via the hydroxy bridge.…”

Section: Introductionmentioning

confidence: 99%

“…In systems of this sort the copper- (11) centres are assumed to be superexchange coupled via the hydroxy bridge. An oxygen bridge, from, e.g., tyrosine or even a hydrox'ide group itself, has been suggested as the superexchange medium for both oxyhemocyanin (9,10) and enzymes containing Type 111 copper centres (8) and other donor groups around the copper centres are thought to include histidine (8, 1 I -13). Metal-metal separatips in pxyhemocyanins are reported to be in excess of 3.50 A (3.55 A (1 2) and 3.67 A (13)) according to EXAFS studies.…”

Section: Introductionmentioning

confidence: 99%

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Structure and magnetism in a hydroxy bridged binuclear copper(II) system with a "tunable" binuclear centre

Thompson¹

1983

Can. J. Chem.

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The molecular structure of [Cu2(PAP)(OH)(IO3)3]•4H2O (PAP = 1,4-di(2′-pyridyl)aminophthalazine) has been determined by single crystal X-ray diffraction. [Cu2(PAP)(OH)(IO3)3]•4H2O belongs to the space group P21/c with a = 7.266(1), b = 15.269(1), c = 25.870(1) Å, β = 96.40(I)°, V = 2852.2 Å3, Z = 4. The copper coordination geometry lies between a square pyramid and a trigonal bipyramid and the two copper(II) centres are bridged by three groups: N2 (phthalazine), hydroxide, and bidentate iodate, in a structure which is analogous to that reported for [Cu2(PAP)(OH)Cl3]•1.5H2O. Replacing the chlorine bridge by iodate has the effect of forcing the two metal centres further apart, thus creating a larger Cu—O—Cu bridge angle. This increase in oxygen bridge angle (101° to 114°) is also reflected in the enhanced antiferromagnetic exchange (−2J(Cl) = 201 cm−1, −2J(IO3) = 335 cm−1). Other groups of varying size (e.g. Br, NO3, SO4) can act as bridges between the two copper centres in systems of this sort with the resultant variation in copper–copper separation and oxygen bridge angle.

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Self-Assembly, Crystal Structure, and Magnetic Properties of a Phenoxo-Bridged Tetranuclear CuII Complex of the [2 × 2] Grid Type

Rojo

Lehn²,

Baum

et al. 1999

Eur. J. Inorg. Chem.

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Binuclear copper complexes: an open and shut case. A strong antiferromagnetically coupled .mu.-monohydroxo bridged complex

Cited by 76 publications

References 2 publications

Copper complexes of polyfunctional phthalazines. Mononuclear and polynuclear derivatives

Copper complexes of polyfunctional phthalazines. Mononuclear and polynuclear derivatives

Structure and magnetism in a hydroxy bridged binuclear copper(II) system with a "tunable" binuclear centre

Self-Assembly, Crystal Structure, and Magnetic Properties of a Phenoxo-Bridged Tetranuclear CuII Complex of the [2 × 2] Grid Type

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