硫脲衍生物及其Cu+配合物的NMR研究

对新的配体硫脲衍生物及其Ｃｕ（Ⅰ）配合物Ｎ－（邻硝基苯基）－Ｎ′－（乙氧基羰基）硫脲（Ｈ２ｏｅｔ）（１）,Ｎ－（对硝基苯基）－Ｎ′－（乙氧基羰基）硫脲（Ｈ２ｐｅｔ）（２）,Ｎ－（对硝基苯基）－Ｎ′－（丁氧基羰基）硫脲（Ｈ２ｐｂｔ）（３）和Ｃｕ（Ｈ２ｏｅｔ）２Ｃｌ（４）,［Ｃｕ（Ｈ２ｐｅｔ）２Ｃｌ］·ＣＨ２Ｃｌ２（５）,［Ｃｕ（Ｈ２ｐｂｔ）２Ｃｌ］２（６）作了１Ｈ、１３Ｃ－ＮＭＲ测定,化合物（１）和（６）还进行了Ｈ－ＨＣＯＳＹ（氢－氢相关二维谱）和ＨＭＱＣ（氢核检测的异核多量子相关谱）２ＤＮＭＲ实验,归属了全部的Ｈ、Ｃ谱线;简单讨论了配合物的配位行为。     

含MoFe3Se4类立方烷核芯簇合物的合成与结构表征

室温下［Ｅｔ_４Ｎ］_２ＭｏＳｅ_４, ＦｅＣｌ_２和 Ｒ_２ＮＣＳ_２Ｎａ在 ＤＭＦ和 ＣＨ_３ＣＮ混合溶剂中反应,得到含ＭｏＦｅ_３Ｓｅ_４核芯的Ｍｏ－Ｆｅ－Ｓｅ簇合物ＭｏＦｅ_３Ｓｅ_４（μ－Ｒ_２ＮＣＳ_２）_２（Ｒ_２ＮＣＳ_２）_４（Ｒ２＝Ｍｅ_２（１）,Ｅｔ_２（２）,Ｃ_４Ｈ_８（３））．化合物２的单晶Ｘ射线衍射分析表明,其分子结构为２个桥式和４个螫合Ｅｔ_２ＮＣＳ_２~－配体包围的一个扭曲类立方烷Ｍ_４Ｓｅ_４簇核对３个化合物的ＣＶ进行了表征,它们在ＤＭＳＯ溶液中的电化学行为表现出了多电子可逆的传递过程．     

大核镉硫簇合物的研究：（Ⅱ）两个八核镉在充簇合物的合成与晶体结构

利用ＣＳ２与镉硫化合物在溶剂中反应产生Ｓ＾２－来合成大核镉硫簇合物，得到了两个新的大核镉硫簇合物，并测定了其晶体结构，化合物（Ⅰ）为（Ｍｅ４Ｎ）２［ＳＣｄ８（ＳＰｈ）１２Ｃｌ４］，晶体属立方晶系，空间群Ｐａ３，ａ＝２６．７８２（３）Ａ，Ｖ＝１９２１１（４）Ａ＾３，Ｄｃ＝１．７５０ｇ／ｃｍ＾３，Ｚ＝８．１６３７个衍射点参与修正，Ｒ＝６．９６％，化合物（Ⅱ）为［Ｃｄ（Ｈ２Ｏ）６］［ＳＣｄ８（ＳＰｈ）１     

环状配合物Me_2Si［η~5－C_5H_4Fe（CO）_2］_2SnR_2的合

通过ＳｎＣｌ_２对化合物Ｍｅ_２Ｓｉ［η~５－Ｃ_５Ｈ_４Ｆｅ（ＣＯ）］_２（μ－ＣＯ）_２（Ⅰ）中Ｆｅ－Ｆｅ键的插入反应以及Ⅰ被Ｎａ－Ｈｇ齐还原所生成的相应双铁负离子｛Ｍｅ_２Ｓｉ［η~５－Ｃ_５Ｈ_４Ｆｅ（ＣＯ）_２］_２｝~（２－）与ＳｎＲ_２Ｃｌ_２（Ｒ＝Ｍｅ，Ｐｈ）的亲核反应，合成了环状化合物Ｍｅ_２Ｓｉ［η~５－Ｃ_５Ｈ_４Ｆｅ（ＣＯ）_２］_２ＳｎＲ_２［Ｒ＝Ｃｌ（１），Ｍｅ（２），Ｐｈ（３）］。以元素分析、ＩＲ和~１ＨＮＭＲ谱表征了它们的结构，并用Ｘ射线衍射测定了配合物３的晶体结构。３为单斜晶系，空间群Ｐ２_１／ｎ，ａ＝１．０３８４（３）ｎｍ，ｂ＝１．６３８４（１）ｎｍ，ｃ＝１．５７６２（５）ｎｍ，β＝９７．９３（２）°，Ｖ＝２．６５６（２）ｎｍ~３，Ｚ＝４，Ｄｘ＝１．７１ｇ／ｍＬ。     

Co3（CO）7（μ3—S）[μ,η^2—SCNC（O）C（R1）（R2）N（COR3）]的…

Ｃｏ２（ＣＯ８）分别与４种硫代乙内酰脲Ｓ＝ＣＮＨＣ（Ｏ）Ｃ（Ｒ１）（Ｒ２）Ｎ（ＣＯＲ３）反就，得到４个新的含硫代乙内酰脲桥基双齿配位的三核钴羰基硫族合物。用元素分析、ＩＲ、＾１Ｈ ＮＭＲ和ＭＳ等手段表征了它们的结构，用Ｘ射线衍射测定了其中一个族合物Ｃｏ３（ＣＯ７）７（μ３－Ｓ）［μ，η＾２－ＳＣＮＣ（Ｏ）Ｃ（ＣＨ３）（ＣＨ３）Ｎ（ＣＯＣＨ３）］（Ⅳ）的晶体结构，晶体属三斜晶系，Ｐ１↑－空间群，晶胞     

稀土脯氨酸配合物[RE_2(L-Pro)_6(H_2O)_4](ClO_4)_6的标准生成焓测定

合成了两种稀土高氯酸盐与Ｌ－脯氨酸配合物的晶体．经热重、差热、化学分析及对比有关文献,知其组成 是［Ｐｒ２（Ｌ－Ｐｒｏ）６（Ｈ２Ｏ）４］（ＣｌＯ４）６和［Ｅｒ２（Ｌ－ＰｒＯ）６（Ｈ２Ｏ）４］（ＣｌＯ４）６,质量分数为９９．２４％和９８．２０％．选用ＲＥ（ＮＯ３）· ６Ｈ２Ｏ（ＲＥ＝Ｐｒ,Ｅｒ）、ＬＰｒｏ、ＮａＣｌＯ４·Ｈ２Ｏ和 ＮａＮＯ３作辅助物,使用具有恒温环境的反应热量计,以 ２ ｍｏｌ·Ｌ－１ＨＣｌ 作溶剂,分别测定了［２ＲＥ（ＮＯ３）３·６Ｈ２Ｏ＋６Ｌ－ＰｒＯ＋６ＮａＣｌＯ４·Ｈ２Ｏ］和｛ ［ＲＥ２（Ｌ－ＰｒＯ）６（Ｈ２Ｏ）４］（ＣｌＯ４）６＋６ＮａＮＯ３｝在 ２９８．１５ Ｋ时的溶解热．设计一热化学循环求得化学反应的反应焓ｒＨ分别是：６３．９０４ ｋＪ·ｍｏｌ－１和 ９１．０１７ ｋＪ·ｍｏｌ－１,经计算得配合物［ＲＥ２（Ｌ－Ｐｒｏ）６（Ｈ２Ｏ）４］（ＣｌＯ４）６（ｓ）在 ２９８．１５ Ｋ时的标准生成焓（２９８．１５ Ｋ）分别 是－６ ５９４．７８ ｋＪ·ｍｏｌ－１和－６ ５３２．８７ ｋＪ·ｍｏｌ－１。     

[Ce(NO_3)_5H_2O]·(C_3H_5N_2)_2的合成、晶体结构及热分析

稀土盐与咪唑形成的化合物可作为植物生长调节剂,具有一定的促进植物生长,抑制杂菌生长的作用［ｌ,２］,而此类化合物的结构数据尚未见报道。本文以水为溶剂,合成了硝酸铈（Ⅲ）与咪唑形成的无色块状晶体［Ｃｅ（ＮＯ３）５Ｈ２Ｏ］·（Ｃ３Ｈ５Ｎ２）２,测定了晶体结构。用热重法推测了其热分解机理。１实验部分１．ｌ［Ｃｅ（ＮＯ３）５Ｈ２Ｏ］·（Ｃ３Ｈ５Ｎ２）２的合成 将０．２ｍｏｌ的Ｃｅ（ＮＯ３）３·６Ｈ２Ｏ和０．５ｍｏｌ的Ｃ３Ｈ４Ｎ２（咪唑）加入到４０ｍＬ水中,用 １ｍｏｌ·Ｌ－１的 ＨＮＯ３水溶液调节 ｐＨ＝ …     

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．     

四甲基双硅桥联环戊二烯基稀土金属有要配合物的合成…

四甲基双硅桥联环戊二烯基钠与无水三氯化稀土在ＴＨＦ溶反应合成了标题配合物Ｍｅ４Ｓｉ２（Ｃ５Ｈ４）２ＬｎＣｌ［Ｌｎ：３Ｎｄ，４Ｓｍ，５Ｇｄ，６Ｙ］和配合物Ｍｅ４Ｓｉ２（Ｃ５Ｈ５）２Ｌｎ（Ｃ５Ｈ５）（ＴＨＦ）ｎ［ＬＮ：１Ｌａ，ｎ＝１；２Ｐｒ，ｎ＝０］。通过元素分析、ＨＮＭＲ、＾１３ＣＮＭＲ和ＭＳ确证了配合物的结构，在ＴＨＦ溶液中重结晶获得配合物４的单晶，Ｘ射线衍证明晶体结构为二聚体。４为单斜晶系，空间     

1—羟基—2（1H）—吡啶硫酮及其甲基衍生物与Au（Ⅲ）配合物的合成和性质

合成了１－羟基－２－（１Ｈ）－吡啶硫酮及其甲基衍生物［ＡｕＬ２］ＯＨ型配合物（Ｌ＝ＰＴ＾－，３－ＣＨ３－ＰＴ＾－Ｔ ４－ＣＨ３－ＰＴ＾－）。用元素，紫外光谱，外红光谱，＾１ＨＮＭＲ谱，摩尔电导，ＴＧＤＴＡ－ＤＴＧ进行了表征，用循环伏安法研究其氧化还原性质，含甲基的配合物有较强的抑菌活性     

Tuning the selectivity/specificity of fluorescent metal ion sensors based on N2S2 pyridine-containing macrocyclic ligands by changing the fluorogenic subunit: spectrofluorimetric and metal ion binding studies

Two new fluorescent chemosensors for metal ions have been synthesized and characterized, and their photophysical properties have been explored; they are the macrocycles 5-(2-quinolinylmethyl)-2,8-dithia-5-aza-2,6-pyridinophane (L5) and 5-(5-chloro-8-hydroxyquinolinylmethyl)-2,8-dithia-5-aza-2,6-pyridinophane (L6). Both systems have a pyridyl-thioether-containing 12-membered macrocycle as a binding site. The coordination properties of these two ligands toward CuII, ZnII, CdII, HgII, and PbII have been studied in MeCN/H2O (1:1 v/v) and MeCN solutions and in the solid state. The stoichiometry of the species formed at 25 degrees C have been determined from absorption, fluorescence, and potentiometric titrations. The complexes [CuL5](ClO4)(2).1/2MeCN, [ZnL5(H2O)](ClO4)2, [HgL5(MeCN)](ClO4)2, [PbL5(ClO4)2], [Cu3(5-Cl-8-HDQH-1)(L6H-1)2](ClO4)(3).7.5H2O (HDQ=hydroxyquinoline), and [Cu(L6)2](BF4)(2).2MeNO2 have also been characterized by X-ray crystallography. A specific CHEF-type response of L5 and L6 to the presence of ZnII and CdII, respectively, has been observed at about pH 7.0 in MeCN/H2O (1:1 v/v) solutions.     

Dinuclear zinc(II) complexes of tetraiminodiphenol macrocycles and their interactions with carboxylate anions and amino acids. Photoluminescence, equilibria, and structure

The reaction equilibria [H(4)L](2+) + Zn(OAc)(2) right harpoon over left harpoon [Zn(H(2)L)](2+) + 2HOAc (K(1)) and [Zn(H(2)L)](2+) + Zn(OAc)(2) right harpoon over left harpoon [Zn(2)L](2+) + 2HOAc (K(2)), involving zinc acetate and the perchlorate salts of the tetraiminodiphenol macrocycles [H(4)L(1)(-)(3)](ClO(4))(2), the lateral (CH(2))(n)() chains of which vary between n = 2 and n = 4, have been studied by spectrophotometric and spectrofluorimetric titrations in acetonitrile. The photoluminescence behavior of the complexes [Zn(2)L(1)](ClO(4))(2), [Zn(2)L(2)(H(2)O)(2)](ClO(4))(2), [Zn(2)L(2)(mu-O(2)CR)](ClO(4)) (R = CH(3), C(6)H(5), p-CH(3)C(6)H(4), p-OCH(3)C(6)H(4), p-ClC(6)H(4), p-NO(2)C(6)H(4)), and [Zn(2)L(3)(mu-OAc)](ClO(4)) have been investigated. The X-ray crystal structures of the complexes [Zn(2)L(2)(H(2)O)(2)](ClO(4))(2), [Zn(2)L(3)(mu-OAc)](ClO(4)), and [Zn(2)L(2)(mu-OBz)(OBz)(H(3)O)](ClO(4)) have been determined. The complex [Zn(2)L(2)(mu-OBz)(OBz)(H(3)O)](ClO(4)) in which the coordinated water molecule is present as the hydronium ion (H(3)O(+)) on deprotonation gives rise to the neutral dibenzoate-bridged compound [Zn(2)L(2)(mu-OBz)(2)].H(2)O. The equilibrium constants (K) for the reaction [Zn(2)L(2)(H(2)O)(2)](2+) + A(-) right harpoon over left harpoon [Zn(2)L(2)A](+) + 2H(2)O (K), where A(-) = acetate, benzoate, or the carboxylate moiety of the amino acids glycine, l-alanine, l-histidine, l-valine, and l-proline, have been determined spectrofluorimetrically in aqueous solution (pH 6-7) at room temperature. The binding constants (K) evaluated for these systems vary in the range (1-8) x 10(5).     

Heteroleptic tris-chelates of ruthenium(II): synthesis, spectral characterisation and electrochemical properties

A facile reaction of cis-trans-cis-RuCl(2)(RaaiR')(2) [RaaiR'=1-alkyl-2-(arylazo)imidazole, m-R-C(6)H(4)-NN-C(3)H(2)-NN-1-R', where R=H (a), OMe (b), NO(2) (c) and R'=Me (1), Et (2) and CH(2)Ph (3)] either with 2,2'-bipyridine (bpy) and AgNO(3) followed by NaClO(4) or [Ag(bpy)(2)](ClO(4)) in boiling acetone has isolated red-brown [Ru(bpy)(RaaiR')(2)](ClO(4))(2) (1a-c, 2a-c, 3a-c). The maximum molecular peak of [Ru(bpy)(OMeaaiMe)(2)](ClO(4))(2) (1b) is observed at m/z 888.01 (100%) in the FAB mass spectrum. IR spectra of the complexes show CN and NN stretching at 1590 and 1370cm(-1) which is red shifted by 40 and 90cm(-1) from the free ligand value supports Ru-azo nitrogen pi bonding interaction. The emission spectra in frozen glass (77K) are sharper and considerably more intense than the room temperature spectra. The (1)H NMR spectral measurements suggest methylene, -CH(2)-, in RaaiEt gives a complex AB type multiplet while in RaaiCH(2)Ph it shows AB type quartets. Considering two arylazoimidazole moieties there are 20 different carbon atoms in the molecule which gives a total of 20 different peaks in the (13)C NMR spectrum. In the (1)H-(1)H COSY spectrum of the present complexes, absence of any off-diagonal peaks extending from delta=14.12 and 9.55ppm confirm their assignment of no proton on N(1) and N(3), respectively. Contour peaks in the (1)H-(13)C HMQC spectrum in the present complexes, the absence of any contours at delta=147.12, 160.76, 155.67 and 157.68 ppm assign them to the C(2), C(6), C(8) and C(e and e') carbon atoms, respectively. Cyclic voltammogram shows Ru(III)/Ru(II) redox couple along with three successive ligand reductions. The plot of difference in potential of first oxidation and reduction versus energy of main MLCT band (nu(CT)) is linear. Electrochemical parametrisation of Ru(III)/Ru(II) redox couple determines ligand potential E(L)(L).     

Cobalt(III) complexes of 3,3′,3′′-triaminotripropylamine (trpn)

The versatility of the carbonato complex [Co(trpn)CO3]ClO4·H2O as a good source for the preparation of a series of octahedral cis-cobalt(III)-trpn complexes was demonstrated. The compound was used to synthesize complexes of the type [Co(trpn)XY]ClO4, where XY= (NO2)2, (OCN)2, (SCN)2, (N3)2, (OH)2, (SCN)(NO2), C6H5O·PO3, p-NO2C6H4OPO3 and DPA. A second series of complexes formulated as [Co(trpn)L](ClO4)2 were prepared where L=phCO2, p-NO2C6H4CO2, pic and amino acid anions of glycine, l-leucine, and l-norvaline, as well as [Co(trpn)(dl-Hpha)](ClO4)3·4H2O (Hpha=phenylalanine). The isolated complexes were characterized by elemental analyses, i.r. and u.v.–vis. spectra. This revised version was published online in June 2006 with corrections to the Cover Date.     

Prepared and characterization of new macrocyclic Schiff bases and their binuclear copper complexes

The new five macrocyclic ligands were synthesized by reaction of 2,6-diaminopyridine and various dialdehydes. Then, their copper(II) perchlorate complexes were synthesized by template effect by reaction of 2,6-diaminopyridine, Cu(ClO(4))(2).6H(2)O and aldehydes. The ligands and their complexes have been characterized by elemental analysis, IR, (1)H and (13)C NMR, UV-vis spectra, magnetic susceptibility, conductivity measurements, mass spectra. All complexes are diamagnetic and binuclear. The diamagnetic behaviour of the binuclear complexes may be explained by a very strong anti-ferromagnetic interaction in the Cu-Cu pair.     

Zinc(II) complexes with intramolecular amide oxygen coordination as models of metalloamidases

Polydentate ligands (6-R1-2-pyridylmethyl)-R2(R1= NHCOtBu, R2= bis(2-pyridylmethyl)amine L1, bis(2-(methylthio)ethyl)amine L2 and N(CH2CH2)2S L3) form mononuclear zinc(II) complexes with intramolecular amide oxygen coordination and a range of coordination environments. Thus, the reaction of Zn(ClO4)2.6H2O with L1-3 in acetonitrile affords [(L)Zn](ClO4)2(L=L1, 1; L2, 2) and [(L3)Zn(H2O)(NCCH3)](ClO4)2 3. The simultaneous amide/water binding in resembles the motif that has been proposed to be involved in the double substrate/nucleophile Lewis acidic activation and positioning mechanism of amide bond hydrolysis in metallopeptidases. X-ray diffraction, 1H and 13C NMR and IR data suggests that the strength of amide oxygen coordination follows the trend 1>2 >3. L1-3 and undergo cleavage of the tert-butylamide upon addition of Me4NOH.5H2O (1 equiv.) in methanol at 50(1)degrees C. The rate of amide cleavage follows the order 1> 2> 3, L1-3. The extent by which the amide cleavage reaction is accelerated in 1-3 relative to the free ligands, L1-3, is correlated with the strength of amide oxygen binding and Lewis acidity of the zinc(II) centre in deduced from the X-ray, NMR and IR studies.     

Fixation of carbon dioxide by macrocyclic lanthanide(III) complexes under neutral conditions producing self-assembled trimeric carbonato-bridged compounds with μ3-η2:η2:η2 bonding

A series of mononuclear lanthanide(III) complexes [Ln(LH(2))(H(2)O)(3)Cl](ClO(4))(2) (Ln = La, Nd, Sm, Eu, Gd, Tb, Lu) of the tetraiminodiphenolate macrocyclic ligand (LH(2)) in 95 : 5 (v/v) methanol-water solution fix atmospheric carbon dioxide to produce the carbonato-bridged trinuclear complexes [{Ln(LH(2))(H(2)O)Cl}(3)(μ(3)-CO(3))](ClO(4))(4)·nH(2)O. Under similar conditions, the mononuclear Y(III) complex forms the dimeric compound [{Y(LH(2))(H(2)O)Cl}(μ(2)-CO(3)){Y(LH(2))(H(2)O)(2)}](ClO(4))(3)·4H(2)O. These complexes have been characterized by their IR and NMR ((1)H, (13)C) spectra. The X-ray crystal structures have been determined for the trinuclear carbonato-bridged compounds of Nd(III), Gd(III) and Tb(III) and the dinuclear compound of Y(III). In all cases, each of the metal centers are 8-coordinate involving two imine nitrogens and two phenolate oxygens of the macrocyclic ligand (LH(2)) whose two other imines are protonated and intramolecularly hydrogen-bonded with the phenolate oxygens. The oxygen atoms of the carbonate anion in the trinuclear complexes are bonded to the metal ions in tris-bidentate μ(3)-η(2):η(2):η(2) fashion, while they are in bis-bidentate μ(2)-η(2):η(2) mode in the Y(III) complex. The magnetic properties of the Gd(III) complex have been studied over the temperature range 2 to 300 K and the magnetic susceptibility data indicate a very weak antiferromagnetic exchange interaction (J = -0.042 cm(-1)) between the Gd(III) centers (S = 7/2) in the metal triangle through the carbonate bridge. The luminescence spectral behaviors of the complexes of Sm(III), Eu(III), and Tb(III) have been studied. The ligand LH(2) acts as a sensitizer for the metal ions in an acetonitrile-toluene glassy matrix (at 77 K) and luminescence intensities of the complexes decrease in the order Eu(3+) > Sm(3+) > Tb(3+).     

三水合高氯酸镨与18-冠-6配合的研究

采用半微量相平衡方法研究了三元体系Pr(ClO4)3.3H2O-18C6-C2H5OH在298.15K的溶解度, 测定了饱和溶液的折光率。该体系在298.15K时生成两种化学计量的配合物: Pr(ClO4)3.18C6.3H2O(1)和Pr(ClO4)3.2(18C6).3H2O(2)。制备了两种固态配合物, 用化学分析, IR, DTG和TG研究了配合物的组成和性质, 采用量热法, 测定了298.15K时18C6, 配合物1和2在乙醇中的积分溶解热, 以及Pr(ClO4)3.3H2O在18C6-C2H5OH溶液中的积分溶解热。利用本文设计的热化学循环, 求得了两种配合物的标准生成焓。     

Yb(Cl_4)_3·3H_2O-18C6-C_2H_5OH体系(25℃)的相化学研究及固态配合物的合成与性质

王冠醚能选择性配位于阳离子,使无机盐溶于有机溶剂及类似酶功能的特性,因而引起人们很大的研究兴趣。文献［１］报道在乙腈中制得了组成为：Ｃｅ（ＣＩＯ４）３·１８Ｃ６的配合物;文献［２］在乙腈中制得了组成为 ＲＥ（ＣＩＯ４） ３· １８Ｃ６（ＲＥ＝ Ｐｒ, Ｅｕｆ）的配合物;而 ＲＥ（ＣＩＯ４） ３·３Ｈ２Ｏ－１８Ｃ６－ＣＨ３ＣＮ体系（ＲＥ＝ Ｄｙ, Ｙ）的相化学研究指出：体系中均形成两种化学计量的配合物［３·４］。Ｙｂ（ＣＩＯ４）３·３Ｈ２Ｏ与１８Ｃ６在乙醇中的配合行为未见报道。为了寻找制备配合物的热力学依…     

Cobalt(III) carbonate and bicarbonate chelate complexes of tripodal tetraamine ligands containing pyridyl donors: the steric basis for the stability of chelated bicarbonate complexes

The synthesis and characterization (X-ray crystallography, UV/vis spectroscopy, electrochemistry, ESI-MS, and (1)H, (13)C, and (59)Co NMR) of the complexes [Co(L)(O(2)CO)]ClO(4)xH(2)O (L = tpa (tpa = tris(2-pyridylmethyl)amine) (x = 1), pmea (pmea = bis((2-pyridyl)methyl)-2-((2-pyridyl)ethyl)amine) (x = 0), pmap (pmap = bis(2-(2-pyridyl)ethyl)(2-pyridylmethyl)amine) (x = 0), tepa (tepa = tris(2-(2-pyridyl)ethyl)amine) (x = 0)) which contain tripodal tetradentate pyridyl ligands and chelated carbonate ligands are reported. The complexes display different colors in both the solid state and solution, which can be rationalized in terms of the different ligand fields exerted by the tripodal ligands. Electrochemical data show that [Co(tepa)(O(2)CO)](+) is the easiest of the four complexes to reduce, and the variation in E(red.) values across the series of complexes can also be explained in terms of the different ligand fields exerted by the tripodal ligands, as can the (59)Co NMR data which show a chemical shift range of over 2000 ppm for the four complexes. [Co(pmea)(O(2)CO)](+) is fluxional in aqueous solution, and VT NMR spectroscopy ((1)H and (13)C) in DMF-d(7) (DMF = dimethylformamide) over the temperature range -25.0 to 75.0 degrees C are consistent with inversion of the unique six-membered chelate ring. This process shows a substantial activation barrier (DeltaG(#) = 58 kJ mol(-1)). The crystal structures of [Co(tpa)(O(2)CO)]ClO(4)xH(2)O, [Co(pmea)(O(2)CO)]ClO(4).3H(2)O, [Co(pmap)(O(2)CO)]ClO(4), and [Co(tepa)(O(2)CO)]ClO(4) are reported, and the complexes containing the asymmetric tripodal ligands pmea and pmap both crystallize as the 6-isomer. The carbonate complexes all show remarkable stability in 6 M HCl solution, with [Co(pmap)(O(2)CO)](+) showing essentially no change in its UV/vis spectrum over 4 h in this medium. The chelated bicarbonate complexes [Co(pmea)(O(2)COH)]ZnCl(4), [Co(pmap)(O(2)COH)][Co(pmap)(O(2)CO)](ClO(4))(3), [Co(pmap)(O(2)COH)]ZnCl(4)xH(2)O, and [Co(pmap(O(2)COH)]ZnBr(4)x2H(2)O can be isolated from acidic aqueous solution, and the crystal structure of [Co(pmap)(O(2)COH)]ZnCl(4)x3H(2)O is reported. The stability of the carbonate complexes in acid is explained by analysis of the crystallographic data for these, and other slow to hydrolyze chelated carbonate complexes, which show that the endo (coordinated) oxygen atoms are significantly hindered by atoms on the ancillary ligands, in contrast to complexes such as [Co(L)(O(2)CO)](+) (L = (NH(3))(4), (en)(2), tren, and nta), which undergo rapid acid hydrolysis and which show no such steric hindrance.