异三核过渡金属配合物〔Fe2Ⅲ MⅡO（OOCC2H5）6L3〕（M=Co,Ni,Mn;L=C5 H5N,H2O）溶液行为的NMR和UV谱表征

A series of new heterotrinuclear transition-metal complexes [(Fe2MO)-M-I-O-I(OOCC2H5)(6)L-3] (M = Co, Ni, Mn; L = C5H5N, H2O) were synthesized and characterized. Their structures and dynamics in different solutions and temperatures were investigated by NMR and UV. Assignments of the H-1 NMR spectra were made on the basis of relative intensities, broadening, substitution with appropriate ligands and spin-lattice relaxation. Experimental results shows that there is antiferromagnetic exchange interaction among the three metal ions within M3O core. It is found that these complexes in DMSO, CD3CN, CDl(3) and CD3COCD3 solvents are stable at room temperature and their structures in solution are the same as their crystal ones. However, the complexes decomposed into carboxylic acid, pyridin and metal ions in water. The results may be helpful in guiding synthesis of similar complexes

SUPPRESSION of REPETITION RATE ARTIFACTS IN COSY－IKE EXPERIMENTS

在脉冲梯度场基础上研究了进一步缩短COSy类2dnMr实验数据采集时间的新方法.利用主动屏蔽梯度场线圈的梯度场恢复时间仅为100μS数量级这一特点，提出一类基于脉冲梯度场消除弛豫假峰的脉冲序列.并以dQf-COSy脉冲序列为例加以验证.实验结果表明：采用文中的方法，取序列重复时间远小于T＿1和T＿2是切实可行的；梯度场技术能很好地抑制弛豫假蜂以达到2dnMk数据的快速采集.In this paper，pulsed Field gradients are used to suppress the rapid－pulsing artiFacts．Due to its superior homospoil charactersitic，pulsed Field gradients ofFer an important method For removal of artiFacts when data is being acquired Fast compared to the relaxation times of the nuclei under study．The experimential results show that the quality of DQF－COSY spectra can be improved by the modiFied pulsc sequence，and the pulsed Field gradients provide a good method For ultra－rapid acquisition 2D COSY－like NMR experiments with suppression the repetition rate artiFacts.福建省自然科学基金;中国科学院福建物质结构研究所所长择优基

Study on the --(95)Mo NMR of Some Mo(W)-Mo-S Cluster Compounds

对含有[MS4]2-（M＝MO，W）单元的一系列钼（钨）-钼-硫簇合物进行了95MOnMr研究，定性分析了95MO化学位移随金属原子配位数、配位金属种类和配位金属配体改变而变化的规律。结果表明，随着[MOS4]2-配位金属原子数的增加，[MOS4]2-上MO的化学位移逐渐向高场移动，这可归因于低氧化态MO0上的电子通过硫桥离域到高氧化态的MO上。为了解析MO0上化学位移的实验结果，采用MM＋力场对[（OC）4MOS2MOS2]2-和[｛（OC）4MO｝MOS4]2-的晶体结构进行几何优化，使之更接近于溶液中的结构，然后利用fEnSkE-HAll方法计算MO原子上的净电荷分布，计算结果较好地好择了MO和MO0化学位移的变化趋势。The 95Mo NMR spectra of some Mo(W) - Mo- S cluster compounds containing [MS4]2-(M=Mo, W) moiety are investigated here.The trends of 95Mo chemical shiFts changing withthe numbers of coordinated metal atoms, the kinds of coordinated metals and the ligands bindingwith coordinated metals are analyzed.It is Found that the chemical shiFt of Mov1 on [MoS4]2-moves to upField as the number of coordinated metal atoms increases.This may be due to thecharge transFer From Mo to Mov1 through S- bridges.In order to prove the experimental data ofMo, the net charges of Mo atoms in [(OC)4MoS2MoS2]2- and [ { (OC)4Mo },MoS4]2- clustersare calculated using Fenske-Hall method based on the optimized crystal structure data.The cal-culated results can reasonably explain the trends of the chemical shiFts of Mo and Mo.结构化学国家重点实验室资助;福建省自然科学基

1H NMR Properties of Trinuclear TransitionMetal \=Complexes M3O(OOCR)6L3+(M=Cr,Fe,Mn; \=R=CH3,C2H5,CH2NH2;L=C5H5N,H2O)

采用1HnMr谱研究了通式为〔M3ⅢO（OOCr）6l3〕＋（M＝Cr，fE，Mn；r＝CH3，C2H5，CH2nH2；l＝C5H5n，H2O）的一系列氧心三核过渡金属配合物，主要考察其1H化学位移随金属、配体、温度、溶剂等因素变化而变化的规律。结果表明，骨架金属对化学位移的影响最大，M3O中的3个金属离子间存在反铁磁交换相互作用。对Mn配合物中顺磁中心对化学位移和线宽的影响机制的研究表明，其1H各向同性位移主要由接触作用贡献A series of oxocentered trinuclear transitionmetal complexes with general formula M3O(OOCR)6L3+(M=Cr,Fe,Mn;R=CH3,C2H5,CH2NH2;L=C5H5N,H2O)were studied by 1H NMR spectra.The investigation was focussed on the change of 1H chemical shifts with various factors such as metals, ligands, temperatures and solvents.The experimental results show that the main effect on chemical shifts comes from skeleton metals and there is antiferromagnetic exchange interaction among the three metal ions within M3O core.For manganese complexes, the influence mechanism s of paramagnetic centers on chemical shifts and peak widths were discussed.It shows that their 1H NMR isotropic shifts are mostly contributed by contact interactions.国家自然科学基金;固体表面物理化学国家重点实验室;结构化学国家重点实验室基

NMR and UV Spectroscopic Characterization on the Solution Behavior of Heterotrinuclear Transition metal Complexes 〔Fe_2~ⅢM~ⅡO(OOC_2H_5)_6L_3〕 (M = Co, Ni, Mn; L = C_5H_5N, H_2O)

在合成和表征了一系列新的异核异价三核过渡金属羧酸配合物〔Fe2 Ⅲ MⅡ O (OOCC2 H5 ) 6 L3〕 (M =Co ,Ni,Mn ;L =C5 H5 N ,H2 O)的基础上 ,利用多种NMR技术并结合UV谱研究了这些配合物在不同溶剂介质和温度下的谱学特征和动力学性质。利用谱峰积分比例、线宽、相同骨架分子的配体取代和纵向弛豫时间对1 HNMR谱进行了归属。实验结果表明 :这类配合物的金属离子间通过中心氧桥存在一定的反铁磁相互作用 ,从而在整体上削弱了顺磁性的影响 ,仍能观察到NMR谱。实验还发现这些配合物在CD3CN和DMSO溶剂中的结构与晶体结构一致 ,而在水中则分解为金属离子、羧酸盐和吡啶。这些结果有助于指导类似配合物的合成A series of new heterotrinuclear transition metal complexes 〔Fe 2 ⅢM ⅡO(OOCC 2H 5) 6L 3〕 (M = Co, Ni, Mn; L = C 5H 5N, H 2O) were synthesized and characterized. Their structures and dynamics in different solutions and temperatures were investigated by NMR and UV. Assignments of the 1H NMR spectra were made on the basis of relative intensities, broadening, substitution with appropriate ligands and spin lattice relaxation. Experimental results shows that there is antiferromagnetic exchange interaction among the three metal ions within M 3O core. It is found that these complexes in DMSO, CD 3CN, CDCl 3 and CD 3COCD 3 solvents are stable at room temperature and their structures in solution are the same as their crystal ones. However, the complexes decomposed into carboxylic acid, pyridin and metal ions in water. The results may be helpful in guiding synthesis of similar complexes.国家自然科学基金! (批准号 :1960 50 0 4 ,2 9832 0 2 0 ) ;; 结构化学国家重点实验室;; 固体表面物理化学国家重点实验室基金资助项

H-1 NMR properties of trinuclear transition-metal complexes [M-3 O-square(OOCR)(6)L-3](+) (M = Cr, Fe, Mn; R = CH3, C2H5,CH2NH2; L = C5H5N, H2O)

A series of oxo-centered trinuclear transition-metal complexes with general formula [(M3O)-O-II(OOCR)(6)L-3](+) (M = Cr, Fe, Mn; R = CH3, C2H5, CH2NH2; L = C5H5N, H2O) were studied by H-1 NMR spectra. The investigation was focussed on the change of H-1 chemical shifts with various factors such as metals, ligands, temperatures and solvents. The experimental results show that the main effect on chemical shifts comes from skeleton metals and there is antiferromagnetic exchange interaction among the three metal ions within M3O core, For manganese complexes, the influence mechanisms of paramagnetic centers on chemical shifts and peak widths were discussed. It shows that their H-1 NMR isotropic shifts are mostly contributed by contact interactions