三取代钨硅杂多配合物的导电性和磁性

合成了α－ＮａｍＨｎ［ＳｉＷ９Ｍ３（Ｈ２Ｏ）３Ｏ３７］·１６Ｈ２Ｏ（Ｍ＝Ｃｏ（Ⅱ），Ｎｉ（Ⅱ），Ｖ（Ⅴ）杂多配合物），通过ＩＣＰ，ＩＲ，ＵＶ，ＴＧ－ＤＴＡ，ＸＰＳ，ＥＰＲ，极谱等手段进行了表征．配合物在室温下的电导率σ值达１×１０－３Ｓ·ｃｍ－１，３４３Ｋ时可达１×１０－２Ｓ·ｃｍ－１，是有实用化前景的新型固体电解质．变温磁化率结果表明α－Ｎａ１０［ＳｉＷ９Ｃｏ３（Ｈ２Ｏ）３Ｏ３７］·１６Ｈ２Ｏ和α－Ｎａ１０［ＳｉＷ９Ｎｉ３（Ｈ２Ｏ）３Ｏ３７］·１６Ｈ２Ｏ具有反铁磁性．     

Magnetic Properties of Heteropoly Complexes α-Na_mH_n[GaW_9M_3(H_2O)_3O_(37)]·16H_2O (M=Co(Ⅱ),Mn(Ⅱ),Cr(Ⅲ))

ＭａｇｎｅｔｉｃＰｒｏｐｅｒｔｉｅｓｏｆＨｅｔｅｒｏｐｏｌｙＣｏｍｐｌｅｘｅｓα┐ＮａｍＨｎ［ＧａＷ９Ｍ３（Ｈ２Ｏ）３Ｏ３７］·１６Ｈ２Ｏ（Ｍ＝Ｃｏ（Ⅱ），Ｍｎ（Ⅱ），Ｃｒ（Ⅲ））＊ＷＡＮＧＬｉ＊＊，ＬＩＵＺｏｎｇ－ｒｕｉ＊＊，ＺＨＯＵＹｕｎ－ｓｈａ...     

杂核簇合物μ_3－CphCoMM＇的合成及结构表征

本文利用等电子金属碎片交换法，由μ３－ＣＰｈＣｏ３（ＣＯ）９（１）与ＮａＭ（ＣＯ）３Ｃｐ’（Ｍ＝Ｍｏ，Ｗ；ＣＰ’＝ＣＨ３Ｃ５Ｈ４）反应根到μ３－ＣＰｈＣｏ２Ｍ（ＣＯ）８ＣＰ’（２ａ，ｂ），μ３—ＣＰｈＣｏＭｏ２（ＣＯ）７Ｃｐ＇２（４），再由２ａ与Ｎａ２［Ｆｅ（ＣＯ）４］反应得到手征性簇合物μ３－ＣＰｈＦｅＣｏＭｏ（ＣＯ）２ＣＰ＇Ｈ（３），对合成的簇合物进行了元素分析、ＩＲ、１ＨＮＭＲ．ＭＳ分析表征．     

含功能取代基的C2Mo2簇合物的合成与晶体结构测定

利用苯乙炔或丙炔醇与「Ｍｏ（ＣＯ）２（η＾５－Ｃ５Ｈ４Ｒ＾１」２「Ｒ＾１＝Ｃ（Ｏ）Ｍｅ,Ｃ（Ｏ）ＯＥｔ,Ｃ（Ｏ）Ｐｈ」的反应合成了６个新的炔烃配位的双钼化合物「Ｍｏ（ＣＯ）２（η＾５－Ｃ５Ｈ４Ｒ＾１）」２（μ－η＾２,η＾２－（ＣＨ＝ＣＲ＾２）「Ｒ＾１＝Ｃ（Ｏ）Ｍｅ,Ｒ＾２＝Ｐｈ,１;Ｒ＾１＝Ｃ（Ｏ）ＯＥｔ,Ｒ＾２＝Ｐｈ,２;Ｒ＾１＝Ｃ（Ｏ）Ｐｈ,Ｒ＾２＝Ｐｈ,３;Ｒ＾１＝Ｃ（Ｏ）Ｍｅ,Ｒ＾２＝Ｃ     

Studies on the Reactivities of Undecatungstogallates K＿n［GaW＿（11）O＿（39）M（H＿2O）］·xH＿2O（M＝Mn，Co，Ni，Cu，Cr，FeorZn）

ＳｔｕｄｉｅｓｏｎｔｈｅＲｅａｃｔｉｖｉｔｉｅｓｏｆＵｎｄｅｃａｔｕｎｇｓｔｏｇａｌｌａｔｅｓＫ＿ｎ［ＧａＷ＿（１１）Ｏ＿（３９）Ｍ（Ｈ＿２Ｏ）］·ｘＨ＿２Ｏ（Ｍ＝Ｍｎ，Ｃｏ，Ｎｉ，Ｃｕ，Ｃｒ，ＦｅｏｒＺｎ）ＬＩＵＪｉｎｇ－ｆｕ，ＺＨＡＮＸｉａｏ－ｐ...     

脱氧核糖核酸变性和损伤的吸附伏安法研究

本文用汞电极（ＨＭＤＥ）二次导数阴极吸附伏安（ＳＤ－ＡｄＣＳＶ）和碳电极（ＧＣＥ、ＣＰＥ）导数循环伏安（ＦＤ－ＣＶ）法研究了核酸受热、紫外线、超声波和丝裂霉素Ｃ（ＭＭＣ）作用下的变性作用。在０．１ｍｏｌ／Ｌ（Ｋ２ＨＰＯ４＋ＫＨ２ＰＯ４）－０．１ｍｏｌ．Ｌ ＮａＣｌ（ｐＨ７．０）底液中，吸附的单股（ｓｓ－）和双螺旋（ｄｓ－）ＤＮＡ分别在ＨＭＤＥ上得到特征还原峰Ｐ３和Ｐ２，和在碳电极上得到氧化峰Ａ。物     

金属键有机化合物的研究──非对称型η~5－取代环戊二烯基三羰基钼（钨）金属单键化合物的合成及表征

通过η５－Ｒ~１Ｃ＿５Ｈ＿４（ＣＯ）＿３ＭＮａ与η~５－Ｒ~２Ｃ＿５Ｈ＿４（ＣＯ）＿３ＭＮａ（Ｍ＝Ｍｏ，Ｗ）以及η~５－Ｒ~１Ｃ＿５Ｈ＿４（ＣＯ）＿３ＭｏＮａ与η~５－Ｒ~２Ｃ＿５Ｈ＿４（ＣＯ）＿３ＷＮａ在Ｆｅ＿２（ＳＯ＿４）＿３醋酸水溶液作用下的交叉氧化偶联反应，合成了７个新的非对称型金属单键化合物η~５－Ｒ~１Ｃ＿５Ｈ＿４（ＣＯ）－３Ｍｏ─Ｍｏ（ＣＯ）＿３Ｃ＿５Ｈ＿４Ｒ~２－η~５（Ｒ~１，Ｒ~２：Ｃ（Ｏ）Ｍｅ，ＣＯ２Ｅｔ），η５－Ｒ１Ｃ５Ｎ４（ＣＯ）３Ｗ─Ｗ（ＣＯ）３Ｃ５Ｈ４Ｒ２－η５（Ｒ１，Ｒ２：Ｃ（Ｏ）Ｍｅ，ＣＯ２Ｅｔ；Ｈ，ＣＯ２Ｅｔ）和η５－Ｒ１Ｃ５Ｈ４（ＣＯ）３Ｍｏ─Ｗ（ＣＯ）３Ｃ５Ｈ４Ｒ２－η５（Ｒ１，Ｒ２：Ｃ（Ｏ）Ｍｅ，Ｈ；Ｅｔ，Ｃ（Ｏ）Ｍｅ；Ｃ（Ｏ）Ｍｅ，ｎ－Ｂｕ；ＣＯ２Ｍｅ，ｎ－Ｂｕ）．用Ｃ／Ｎ分析、ＩＲ、１ＨＮＭＲ和ＭＳ表征了它们的结构，并对该氧化偶联反应的特点进行了讨论．     

非对称Schiff碱过渡金属配合物模拟酶催化烯烃环氧化（I）

研究了温和条件下以亚碘酰苯为氧源，非对称性的和对称性的Ｍｎ（Ⅲ）Ｓｃｈｉｆｆ碱配合物「Ｍｎ（Ⅲ）（ＣＢＰ－ｐｈｅｎ－Ｘｓａｌ）Ｃｌ，Ｘ＝Ｈ，Ｃｌ，Ｂｒ，Ｎｏ２，Ｃｈ３，ＯＣＨ３」和「Ｍｎ（Ⅲ）（ＣＢＰ－Ｒ－ＣＢＰ）Ｙ，Ｒ＝ＣＨ２ＣＨ２－，－ＣＨ（ＣＨ３）ＣＨ２－，－Ｃ６Ｈ４－；Ｙ＝Ｃｌ，ＯＣＨ３」催化非官能性烯烃苯乙烯，环己烯和α甲基苯乙烯的环氧化反应，结果表明，非对称配合物Ｍｎ（Ⅲ）的电子结合能     

THE REACTION OF（μ_3－CPh）Co_3（CO）_9 WITH TRANSITION METAL CARBONYL ANION M（CO）_3（RCOCp）AND CHARACTERIZATION OF CLUSTERS（μ_3－CPh）CO_2M（CO）_8（RCOCPp）（M＝Mo，W；R＝H，CH_3．C_2H_5O）

ＴＨＥＲＥＡＣＴＩＯＮＯＦ（μ_３－ＣＰｈ）Ｃｏ_３（ＣＯ）_９ＷＩＴＨ　ＴＲＡＮＳＩＴＩＯＮＭＥＴＡＬＣＡＲＢＯＮＹＬＡＮＩＯＮＭ（ＣＯ）_３（ＲＣＯＣｐ）ＡＮＤＣＨＡＲＡＣＴＥＲＩＺＡＴＩＯＮＯＦＣＬＵＳＴＥＲＳ（μ_３－ＣＰｈ）ＣＯ_２Ｍ（ＣＯ）_８（ＲＣＯＣＰｐ）（Ｍ＝Ｍｏ，Ｗ；Ｒ＝Ｈ，ＣＨ_３．Ｃ_２Ｈ_５Ｏ）Ａｕｔｈｏｒｔｏｗｈｏｍｃｏｒｍｓｐｏｎｄｅｎｃｅｓｈｏｕｌｄａｄｄｒｅｓｓｅｄ．ＥｘｐｅｒｉｍｅｎｔａｌｓｅｃｔｉｏｎＧｅｎｅｒａｌｐｒｏｃｅｄｕｒｅａｎｄｍａｔｅｒｉａｌＡｌｌｏｐｅｒａｔｉｏｎｗａｓｃａｒｒｉｅｄｏｕｔｕｎｄｅｒｈｉｇｈｌｙｐｕｒｅｎｉｔｒｏｇｅｎａｔｍｏｓｐｈｅｒｅｕｓｉｎｇｓｈａｄａｒｄＳｃｈｌｅｎｌｃａｎｄｖａｃｕｕｍｔｅｃｈｎｉｑｕｅｓ．Ｈｅ－ｃａｎｅ，ｂｅｎｚｅｎｅａｎｄｔｅｔｒａｈｙｄｒｏｆｕｒａｎｗｅｒｅｐｒｅｄｒｉｅｄｏｖｅｒｓｏｄｉｕｍｗｉｒｅａｎｄｄｉｓｔｉｌｌｅｄｆｒｏｍｓｏｄｉｕｍ－ｂｅｎｚｏｐｈｅｎｏｎｅｕｎｄｅｒｎｉｔｒｏｇｅｎ．ＮａＭ（ＣＯ）３（ＲＣＯＣＰ）ａｎｄＰｈＣＣｏ３（ＣＯ），ｗｅｒｅｐｒｅｐａｒｅｄａｃｃｏｒｄｉｎｇｔｏｌｉｔｅｒａｔＵｒｅ     

RE[CH2（CH2）4CONC4H9]3（NO3）3（RE=La,Dy）的合成和晶体结构

采用Ｘ－射线四园衍射仪测定了Ｄｙ「Ｃｈ２（ＣＨ２）４ＣＯＮＣ４Ｈ９」３（ＮＯ３）３和Ｌａ「ＣＨ２（ＣＨ２）４ＣＯＮＣ４Ｈ３」３（ＮＯ３）３的晶体结构。两个配合物具有相似的结构，均属单斜晶系，空间群为Ｐ２１／ｃ。晶体参数：Ｄｙ「Ｌａ」：ａ＝１．８５６４（３）「１．８５６４（２）」ｎｍ，ｂ＝０．９７６９（２）「０．９８３４（１）」ｎｍ，ｃ＝２．１８６３（６）「２．２００３８（７）」ｎｍ，β＝９６．０８     

Synthesis, structure, and magnetic properties of valence ambiguous dinuclear antiferromagnetically coupled cobalt and ferromagnetically coupled iron complexes containing the chloranilate(2-) and the significantly stronger coupling chloranilate(*3-) radical trianion

Dinuclear [(TPyA)MII(CA2-)MII(TPyA)]2+ [TPyA=tris(2-pyridylmethyl)amine; CA2-=chloranilate dianion; M=Co (1(2+)), Fe (2(2+))] complexes have been prepared by the reaction of M(BF4)(2).6H2O, TPyA, H2CA, and triethylamine in MeOH solution. Their reduced forms [(TPyA)MII(CA*3-)MII(TPyA)]+ [M=Co(1+), Fe (2+)] have been synthesized by using cobaltocene, and oxidized forms of 1, [(TPyA)CoIII(CAn)CoIII(TPyA)]z+ [z=3, n=3- (1(3+)); z=4, n=2- (1(4+))], have been obtained by using FcBF4 and ThianBF4 (Fc=ferrocenium; Thian=thianthrinium), respectively. The dinuclear compound bridged chloranilates (CA2- or CA*3-) were isolated and characterized by X-ray crystallography, electrochemistry, magnetism, and EPR spectroscopy. Unlike the other redox products, valence ambiguous 13+ forms via a complex redox-induced valence electron rearrangement whereby the one-electron oxidation of the [CoIICA2-CoII]2+ core forms [CoIIICA*3-CoIII]3+, not the expected simple 1-e- transfer mixed-valent [CoIICA2-CoIII]3+ core. The M ions in 1 and 2 have a distorted octahedral geometry by coordination with four nitrogens of a TPyA, two oxygens of a chloranilate. Due to the interdimer offset face-to-face pi-pi and/or herringbone interactions, all complexes show extended 1-D and/or 2-D supramolecular structures. The existence of CA*3- in 1(3+) is confirmed from both solid-state magnetic and solution EPR data. Co-based 1n+ exhibit antiferromagnetic interactions [1(2+): g=2.24, J/kB=-0.65 K (-0.45 cm-1); 1+: g=2.36, J/kB=-75 K (52 cm-1)], while Fe-based 2n+ exhibit ferromagnetic interactions [2(2+): g=2.08, J/kB=1.0 K (0.70 cm-1); 2+: g=2.03, J/kB=28 K (19 cm-1)] [H=-2JS1.S2 for 12+ and 2(2+); H=-2J(S1.S2+S2.S3) for 1+ and 2+]. Thus, due to direct spin exchange CA*3- is a much strong spin coupling linkage than the superexchange spin-coupling pathway provided by CA2-.     

N,N'-乙二水杨酰胺合铜(II)酸根和N,N'-1,2-丙二水杨酰胺全铜(II)酸根的双核Cu(II)-Fe(III)配合物的合成和磁性

本文合成了四个新型双核配合物、[Cu(samen)Fe(L)Cl]和[Cu(sampn)Fe(L)Cl]。经元素分析、IR, 电导、磁性测量等手段推定配合物具有酚氧桥结构, Cu(II)及Fe(III)的配位环境分别为平面四方及四角锥的构型, Fe(III)离子的自旋态S=3/2。测定了配合物[Cu(samen)Fe(L)Cl]的变温磁化率(4-300K), 参数J和θ值表明两个双核配合物中金属离子之间有中等程度的反铁磁性超交换作用和双核单元之间有弱的分子间相互作用。     

A Raman spectroscopic study of the uranyl phosphate mineral bergenite

Raman spectroscopy at 298 and 77 K of bergenite has been used to characterise this uranyl phosphate mineral. Bands at 995, 971 and 961 cm-1 (298 K) and 1006, 996, 971, 960 and 948 cm-1 (77K) are assigned to the nu1(PO4)3- symmetric stretching vibration. Three bands at 1059, 1107 and 1152 cm-1 (298 K) and 1061, 1114 and 1164 cm-1 (77 K) are attributed to the nu3(PO4)3- antisymmetric stretching vibrations. Two bands at 810 and 798 cm-1 (298 K) and 812 and 800 cm-1 (77 K) are attributed to the nu1 symmetric stretching vibration of the (UO2)2+ units. Bands at 860 cm-1 (298 K) and 866 cm-1 (77 K) are assigned to the nu3 antisymmetric stretching vibrations of the (UO2)2+ units. UO bond lengths in uranyls, calculated using the wavenumbers of the nu1 and nu3(UO2)2+ vibrations with empirical relations by Bartlett and Cooney, are in agreement with the X-ray single crystal structure data. Bands at (444, 432, 408 cm-1) (298 K), and (446, 434, 410 and 393 cm-1) (77 K) are assigned to the split doubly degenerate nu2(PO4)3- in-plane bending vibrations. The band at 547 cm-1 (298 K) and 549 cm-1 (77 K) are attributed to the nu4(PO4)3- out-of-plane bending vibrations. Raman bands at 3607, 3459, 3295 and 2944 cm-1 are attributed to water stretching vibrations and enable the calculation of hydrogen bond distances of >3.2, 2.847, 2.740 and 2.637 A. These bands prove the presence of structurally nonequivalent hydrogen bonded water molecules in the structure of bergenite.     

Synthesis, characterization and magnetism of binuclear cobalt (II) complexes bridged by tetracarboxylato groups

Three new binudear cobalt (II) complexes with extended te-tracarboxylato- bridge have been synthesized and characterized, namely [Co2 (PMTA) (bpy)4] (1), [Co2(PMTA)-(phen)4] (2) and [Co2(PMTA) (NO2phen)4] (3), where PMTA represents the tetraanion of pyroniellitic acid, and bpy, phen, NO2-phen denote 2,2'-bipyridine, 1,10-phenan-throline; 5-nirto-1, 10-plienanthroline, respectively. Based on elemental analyses, molar conductivity measurements, IR and electronic spectra studies, it is proposed that these complexes have PMTA-bridged structures and consist of two cobalt (II) ions, each in a distorted octahedral environment. These complexes were further characterized by variable temperature magnetic susceptibility measurements (4-300 K) and the observed data were successfully simulated by the equation based on the spin Hamiltonian operator, giving the exchange integral J = - 1.02 cm-1 for 1, J = -1.21 cm-1 for 2 and J = - 1.18 cm-1 for 3, respectively. These results revealed the operation of antiferromagneti     

Noble gas-actinide compounds: evidence for the formation of distinct CUO(Ar)(4-n)(Xe)(n) and CUO(Ar)(4-n)(Kr)(n) (n = 1, 2, 3, 4) complexes

Laser-ablated U atoms react with CO in excess argon to produce CUO, which gives rise to 852.5 and 804.3 cm-1 infrared absorptions for the triplet state CUO(Ar)n complex in solid argon at 7 K. Relativistic density functional calculations show that the CUO(Ar) complex is stable and that up to four or five argon atoms can complex to CUO. When 1-3% Xe is added to the argon/CO reagent mixture, strong absorptions appear at 848.0 and 801.3 cm-1 and dominate new four-band progressions, which increase on annealing to 35-50 K as Xe replaces Ar in the intimate coordination sphere. Analogous spectra are obtained with 1-2% Kr added. This work provides evidence for eight distinct CUO(Ng)n(Ar)4-n (Ng = Kr, Xe, n = 1, 2, 3, 4) complexes and the first characterization of neutral complexes involving four noble-gas atoms on one metal center.     

Inorganic-organic hybrid membranes with anhydrous proton conduction prepared from 3-aminopropyltriethoxysilane and sulfuric acid by the sol-gel method

Inorganic-organic hybrid membranes with anhydrous proton conduction were prepared from 3-aminopropyltriethoxysilane and H2SO4 by the sol-gel method. The membrane has a unique structure: a hexagonal phase formed by the stacking of rodlike polysiloxanes with ion complexes of ammonium groups and HSO4- extruded outside. The membranes showed high conductivity of 2 x 10-3 S cm-1 at 200 degrees C under dry atmosphere. In the membrane, protons probably migrate through the outside of the rodlike polysiloxanes along hydrogen-bond chains formed among HSO4- anions.     

Ship-in-bottle formation of Ru_3(CO)_(12) in NaY zeolite

NaY zeolite entrapped Ru3(CO)12 cluster has been synthesized from RuCl3 ion-exchanged NaY, which is well characterized by IR and Raman spectroscopies and CO chemisorp-tion. When the Ru3+/NaY sample is heated from 298 K to 393 K for 25 h and for 10 h at 393 K, the sample colour changes from dark to brown-yellow. The in situ infrared spectrum exhibits absorption bands at 2130, 2064, 2040, 2017, 1990, 1953 and 1925 cm-1. The bands at 2130 cm-1 arises from the Runm+(CO)l m =1-3;n = 1 - 3; l = 1-12). The bands at 2064, 2040, 2017 and 1990 cm-1 are proposed to be associated with the Ru3(CO)12/NaY, which are close to Ru3(CO)12 crystalline. Furthermore, the Raman results provide bands at 150 and 185 cm-1, which can be attributed to Ru-Ru bonds of the sample as in the case of Ru3(CO)12 crystalline, for which the A1' Ru-Ru stretching mode is assigned to 185 cm-1 and E1' Ru-Ru stretching mode is assigned to a band at 150 cm-1, respectively. CO chemisorption of [Ru3]/NaY gives a CO/Ru ratio of 3.85, which is simila     

气相中开壳型(CH3)2S(O)…HOO红移氢键复合物的结构与性质

在DFT-B3LYP/6-311++G**水平上分别求得(CH3)2S…HOO和(CH3)2O…HOO开壳型氢键复合物势能面上的稳定构型. 频率分析表明, 与单体HOO自由基相比, 复合物中H10-O11键伸缩振动频率发生显著的红移, 红移值分别为424.21和374.22 cm-1. 在MP2/6-311++G**水平计算得到, 含基组重叠误差(BSSE)校正和零点振动能(ZPVE)校正的相互作用能分别为-24.68和-31.01 kJ·mol-1. 自然键轨道(NBO)理论分析表明, 在(CH3)2S…HOO复合物中, 引起H10-O11键变长的因素包括两种电荷转移: (1) LP(S1)1→σ*(H10-O11); (2) LP(S1)2→σ*(H10-O11), 其中LP(S1)2→σ*(H10-O11)占主要作用, 总的结果是使σ*(H10-O11)的自然布居数增加了37.27 me; 在(CH3)2O…HOO中也有相似的电荷转移的超共轭作用. AIM理论分析表明, S1…H10间和O1…H10间都存在键鞍点, ▽2ρ(r)分别为0.06196和0.03745, 说明这种相互作用介于共价键和离子键之间, 偏于静电作用.     

New linear high-valent tetranuclear manganese-oxo cluster relevant to the oxygen-evolving complex of photosystem II with oxo, hydroxo, and aqua coordinated to a single Mn(IV)

An unprecedented atom connectivity, MnIV(mu-O)MnIV(mu-O)2MnIV(mu-O)MnIV, is found in the complex [MnIV4O4(EtO-terpy)4(OH)2(OH2)2](ClO4)(6).8H2O (EtO-terpy=4'-ethoxyl-2,2':6',2' '-terpyridine), which has been characterized by X-ray crystallography, X-ray powder diffraction, EPR spectroscopy, and magnetic studies. This complex is the first example of a compound where a MnIV ion is coordinated by all three types of water-derived ligands: oxo, hydroxo, and aqua. Bond distances and angles for this complex are consistent with a MnIV4 oxidation state assignment. The di-mu-oxo- and mono-mu-oxo-bridged Mn-Mn distances are 2.80 and 3.51 A, respectively. The variable-temperature magnetic susceptibility data for this complex, in the range of 10-300 K, are consistent with an S=0 ground state and were fit using the spin Hamiltonian HHDvV=-J1S2S1-J2S1S1A-J1S1AS2A (S1=S1A=S2=S2A=3/2) with J1=-432 cm-1 and J2=-164 cm-1 (where J1 and J2 are exchange constants through the mono-mu-oxo and the di-mu-oxo bridges, respectively). The first excited spin state of this tetramer is a spin triplet state at 279 cm-1 above the diamagnetic ground state. The next spin states are the S=1 and S=2 levels at about 700 and 820 cm-1 above the S=0 ground state, respectively. These large energy gaps are consistent with the absence of an EPR signal for this complex, even at high temperature.     

Magnetic properties of diruthenium(II,III) carboxylate compounds with large zero-field splitting and strong antiferromagnetic coupling

The magnetic properties of mixed-valent compounds of general formula Ru2Cl(mu-O2CR)4 [R = CH2-CH3 (1), C(Me)=CHEt) (2)] have been studied in the 2-300 K temperature range. This magnetic study also includes a revision of the magnetic properties of the complex Ru2Cl(mu-O2CCMePh2)4 (3). Compounds 1-3 show a linear structure and a strong antiferromagnetic coupling between the diruthenium units through the chlorine atoms according to previous studies. Two fitting models to explain the magnetic properties of these complexes that incorporate a large zero-field splitting together with a strong antiferromagnetic coupling are described. These models consider that each diruthenium unit (S = 3/2) is magnetically coupled to the nearest diruthenium unit and ignores the longer distance magnetic coupling. The fitting models were found to be successful in fitting the magnetic data of the linear diruthenium(II,III) complexes. The zero-field splitting, D, and the antiferromagnetic coupling, zJ, vary from 37.8 to 48.0 cm-1 and from -7.43 to -13.30 cm-1, respectively, for complexes. The D values are similar to those calculated for the nonlinear diruthenium(II,III) compounds and confirm the validity of the proposed fitting models.