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1.
The amino substituted bidentate chelating ligand 2‐amino‐5‐(2‐pyridyl)‐1,3,4‐thiadiazole (H2 L ) was used to prepare 3:1‐type coordination compounds of iron(II), cobalt(II) and nickel(II). In the iron(II) perchlorate complex [FeII(H2 L )3](ClO4)2·0.6MeOH·0.9H2O a 1:1 mixture of mer and fac isomers is present whereas [FeII(H2 L )3](BF4)2·MeOH·H2O, [CoII(H2 L )3](ClO4)2·2H2O and [NiII(H2 L )3](ClO4)2·MeOH·H2O feature merely mer derivatives. Moessbauer spectroscopy and variable temperature magnetic measurements revealed the [FeII(H2 L )3]2+ complex core to exist in the low‐spin state, whereas the [CoII(H2 L )3]2+ complex core resides in its high‐spin state, even at very low temperatures. 相似文献
2.
Zhong Yu Atsuhiro Nabei Takafumi Izumi Takashi Okubo Takayoshi Kuroda‐Sowa 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(5):m209-m212
4′‐Cyanophenyl‐2,2′:6′,2′′‐terpyridine (cptpy) was employed as an N,N′,N′′‐tridentate ligand to synthesize the compounds bis[4′‐(4‐cyanophenyl)‐2,2′:6′,2′′‐terpyridine]cobalt(II) bis(tetrafluoridoborate) nitromethane solvate, [CoII(C22H14N4)2](BF4)2·CH3NO2, (I), and bis[4′‐(4‐cyanophenyl)‐2,2′:6′,2′′‐terpyridine]cobalt(III) tris(tetrafluoridoborate) nitromethane sesquisolvate, [CoIII(C22H14N4)2](BF4)3·1.5CH3NO2, (II). In both complexes, the cobalt ions occupy a distorted octahedral geometry with two cptpy ligands in a meridional configuration. A greater distortion from octahedral geometry is observed in (I), which indicates a different steric consequence of the constrained ligand bite on the CoII and CoIII ions. The crystal structure of (I) features an interlocked sheet motif, which differs from the one‐dimensional chain packing style present in (II). The lower dimensionality in (II) can be explained by the disturbance caused by the larger number of anions and solvent molecules involved in the crystal structure of (II). All atoms in (I) are on general positions, and the F atoms of one BF4− anion are disordered. In (II), one B atom is on an inversion center, necessitating disorder of the four attached F atoms, another B atom is on a twofold axis with ordered F atoms, and the C and N atoms of one nitromethane solvent molecule are on a twofold axis, causing disorder of the methyl H atoms. This relatively uncommon study of analogous CoII and CoIII complexes provides a better understanding of the effects of different oxidation states on coordination geometry and crystal packing. 相似文献
3.
Ellery R. Garbelini Manfredo Hrner Mariana Boneberger Behm David J. Evans Fbio S. Nunes 《无机化学与普通化学杂志》2008,634(10):1801-1806
The pyridine‐2‐carbaldehyde semicarbazone ligand (HL) reacts with iron(II) and copper(II) perchlorates in boiling ethanol to yield red‐violet [FeII(HL)2](ClO4)2·H2O ( 1 ) and light‐green crystals [CuII(HL)2](ClO4)2·H2O ( 2 ). The crystals are triclinic with the metal ions in an octahedral environment, coordinated to two nitrogen and one oxygen‐donor atom from HL. Electronic, magnetic and electrochemical properties are presented as well. 相似文献
4.
Trinuclear [CoIII2–LnIII] (Ln=Tb,Dy) Single‐Ion Magnets with Mixed 6‐Chloro‐2‐Hydroxypyridine and Schiff Base Ligands 下载免费PDF全文
Prof. Dr. Cai‐Ming Liu Prof. Dr. De‐Qing Zhang Prof. Dr. Xiang Hao Prof. Dao‐Ben Zhu 《化学:亚洲杂志》2014,9(7):1847-1853
The Schiff base ligand N1,N3‐bis(3‐methoxysalicylidene)diethylenetriamine (H2valdien) and the co‐ligand 6‐chloro‐2‐hydroxypyridine (Hchp) were used to construct two 3d–4f heterometallic single‐ion magnets [Co2Dy(valdien)2(OCH3)2(chp)2] ? ClO4 ? 5 H2O ( 1 ) and [Co2Tb(valdien)2(OCH3)2(chp)2] ? ClO4 ? 2 H2O ? CH3OH ( 2 ). The two trinuclear [CoIII2LnIII] complexes behave as a mononuclear LnIII magnetic system because of the presence of two diamagnetic cobalt(III) ions. Complex 1 has a molecular symmetry center, and it crystallizes in the C2/c space group, whereas complex 2 shows a lower molecular symmetry and crystallizes in the P21/c space group. Magnetic investigations indicated that both complexes are field‐induced single‐ion magnets, and the CoIII2–DyIII complex possesses a larger energy barrier [74.1(4.2) K] than the CoIII2–TbIII complex [32.3(2.6) K]. 相似文献
5.
《Chemistry (Weinheim an der Bergstrasse, Germany)》2006,12(2):489-498
The new compounds [(acac)2Ru(μ‐boptz)Ru(acac)2] ( 1 ), [(bpy)2Ru(μ‐boptz)Ru(bpy)2](ClO4)2 ( 2 ‐(ClO4)2), and [(pap)2Ru(μ‐boptz)Ru(pap)2](ClO4)2 ( 3 ‐(ClO4)2) were obtained from 3,6‐bis(2‐hydroxyphenyl)‐1,2,4,5‐tetrazine (H2boptz), the crystal structure analysis of which is reported. Compound 1 contains two antiferromagnetically coupled (J=?36.7 cm?1) RuIII centers. We have investigated the role of both the donor and acceptor functions containing the boptz2? bridging ligand in combination with the electronically different ancillary ligands (donating acac?, moderately π‐accepting bpy, and strongly π‐accepting pap; acac=acetylacetonate, bpy=2,2′‐bipyridine pap=2‐phenylazopyridine) by using cyclic voltammetry, spectroelectrochemistry and electron paramagnetic resonance (EPR) spectroscopy for several in situ accessible redox states. We found that metal–ligand–metal oxidation state combinations remain invariant to ancillary ligand change in some instances; however, three isoelectronic paramagnetic cores Ru(μ‐boptz)Ru showed remarkable differences. The excellent tolerance of the bpy co ‐ ligand for both RuIII and RuII is demonstrated by the adoption of the mixed ‐ valent form in [L2Ru(μ‐boptz)RuL2]3+, L=bpy, whereas the corresponding system with pap stabilizes the RuII states to yield a phenoxyl radical ligand and the compound with L=acac? contains two RuIII centers connected by a tetrazine radical‐anion bridge. 相似文献
6.
This article deals with the hitherto unexplored metal complexes of deprotonated 6,12‐di(pyridin‐2‐yl)‐5,11‐dihydroindolo[3,2‐b]carbazole (H2L). The synthesis and structural, optical, electrochemical characterization of dimeric [{RuIII(acac)2}2(μ‐L.?)]ClO4 ([ 1 ]ClO4, S=1/2), [{RuII(bpy)2}2(μ‐L.?)](ClO4)3 ([ 2 ](ClO4)3, S=1/2), [{RuII(pap)2}2(μ‐L2?)](ClO4)2 ([ 4 ](ClO4)2, S=0), and monomeric [(bpy)2RuII(HL?)]ClO4 ([ 3 ]ClO4, S=0), [(pap)2RuII(HL?)]ClO4 ([ 5 ]ClO4, S=0) (acac=σ‐donating acetylacetonate, bpy=moderately π‐accepting 2,2’‐bipyridine, pap=strongly π‐accepting 2‐phenylazopyridine) are reported. The radical and dianionic states of deprotonated L in isolated dimeric 1 +/ 2 3+ and 4 2+, respectively, could be attributed to the varying electronic features of the ancillary (acac, bpy, and pap) ligands, as was reflected in their redox potentials. Perturbation of the energy level of the deprotonated L or HL upon coordination with {Ru(acac)2}, {Ru(bpy)2}, or {Ru(pap)2} led to the smaller energy gap in the frontier molecular orbitals (FMO), resulting in bathochromically shifted NIR absorption bands (800–2000 nm) in the accessible redox states of the complexes, which varied to some extent as a function of the ancillary ligands. Spectroelectrochemical (UV/Vis/NIR, EPR) studies along with DFT/TD‐DFT calculations revealed (i) involvement of deprotonated L or HL in the oxidation processes owing to its redox non‐innocent potential and (ii) metal (RuIII/RuII) or bpy/pap dominated reduction processes in 1 + or 2 2+/ 3 +/ 4 2+/ 5 +, respectively. 相似文献
7.
Prof. Biing‐Chiau Tzeng Sheng‐Luen Wei Dr. Tsung‐Yi Chang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(51):16443-16449
We have synthesized a series of 1D double‐zigzag ({[Cd(paps)2(H2O)2](ClO4)2}n ( 1 ), {[Cd(papo)2(H2O)2](ClO4)2}n ( 3 ), and {[Cd(papc)2(H2O)2](ClO4)2}n ( 5 )) and 2D polyrotaxane frameworks ([Cd(papc)2(ClO4)2]n ( 6 )) by the reaction of Cd(ClO4)2 with dipyridylamide ligands N,N′‐bis(pyridylcarbonyl)‐4,4′‐diaminodiphenyl thioether (paps), N,N′‐bis(pyridylcarbonyl)‐4,4′‐diaminodiphenyl ether (papo), and N,N′‐(methylenedi‐p‐phenylene)bispyridine‐4‐carboxamide (papc), respectively, where their molecular structures have been determined by X‐ray diffraction studies. Based on the powder X‐ray data (PXRD) of compound 3 and its ZnII analogue, heating the double‐zigzag framework of compound 3 can give the polyrotaxane framework of [Cd(papo)2(ClO4)2]n ( 4 ) and grinding this powder sample in the presence of moisture resulted in its complete conversion back into the pure double‐zigzag framework. In addition, heating the double‐zigzag frameworks of compounds 1 and 5 can induce structural transformation into their respective polyrotaxanes, whereas grinding these solid samples in the presence of moisture did not lead to the formation of the double zigzags. Herein, we investigated the effect of the metal (from ZnII to CdII) on the assembly process and luminescence properties, as well as on the particularly intriguing structural transformation of a series of papx‐based frameworks. In fact, the assembly behavior and luminescence properties of the CdII? papx and ZnII? papx frameworks were really similar. However, both ZnII? papx (x=s, o) frameworks can perform reversible structural transformation, but only the CdII? papo framework can do it. Therefore, a delicate metal effect on such a new structural transformation can be observed. 相似文献
8.
Counter‐Anion‐Regulated Mixed‐Valency of Cobalt(II/III) Centers in a Metallosupramolecular Framework
A diamagnetic AuI4CoIII2 hexanuclear complex, [Au4Co2(dppe)2(l ‐nmc)4]2+ ([ 1L ‐ nmc ]2+; dppe=1,2‐bis(diphenylphosphino)ethane, l ‐H2nmc=N‐methyl‐l ‐cysteine), was newly synthesized by the reaction of [Co(l ‐nmc)2]? with [Au2Cl2(dppe)] and crystallized with different inorganic anions (X=ClO4?, NO3?, Cl?, SO42?) to produce ionic solids ([ 1L ‐ nmc ]Xn). Single‐crystal X‐ray analysis revealed that all the solids crystallize in the chiral space group F432 with a face‐centered‐cubic lattice structure consisting of supramolecular octahedra of complex cations. The paramagnetic nature of all the solids was evidenced by magnetic susceptibility measurements, showing the variation of the oxidation states of two cobalt centers in [ 1L ‐ nmc ]n+ from CoII1.00CoIII1.00 for X=ClO4? or NO3? to CoII0.67CoIII1.33 for X=Cl?, via CoII0.83CoIII1.17 for X=SO42?. The difference in the CoII/III mixed‐valences was explained by the difference in sizes and charges of counter anions accommodated in lattice interstices with a fixed volume. 相似文献
9.
Fatma Karipcin Burcin Culu Saroj K. Sharma Kushal Qanungo 《Helvetica chimica acta》2012,95(4):647-659
The reaction of the ‘oximato’‐ligand precursor A (Fig. 1) and metal salts with KCN gave two mononuclear complexes [ML(CN)(H2O)n](ClO4) ( 1 and 2 ; L={N‐(hydroxy‐κO)‐α‐oxo‐N′‐[(pyridin‐2‐yl‐κN)methyl[1,1′‐biphenyl]‐4‐ethanimidamidato‐κN′}; M=CoII ( 1 ), CuII ( 2 ); n=2 for CoII, n=0 for CuII; Figs. 2 and 3). The new cyano‐bridged pentanuclear ‘oximato’ complexes [{ML(H2O)n(NC)}4M1(H2O)x](ClO4)2 ( 3 – 6 ) and trinuclear complexes [{ML(H2O)n(NC)}2M1L](ClO4) ( 7 – 10 ) ([M1=MnII, CuII; x=2 for MnII, x=0 for CuII] were synthesized from mononuclear complexes and characterized by elemental analyses, magnetic susceptibility, molar conductance, and IR and thermal analysis. The four [ML(CN)(H2O)n]+ moieties are connected by a metal(II) ion in the pentanuclear complexe 3 – 6 , each one involving four cyano bridging ligands (Fig. 4). The central metal ion displays a square‐planar or octahedral geometry, with the cyano bridging ligands forming the equatorial plane. The axial positions are occupied by two aqua ligands in the case of the central Mn‐atom. The two [ML(CN)(H2O)n]+ moieties and an ‘oximato’ ligand are connected by a metal(II) ion in the trinuclear complexes 7 – 10 , each one involving two cyano bridging ligands (Fig. 5). The central metal ions display a distorted square‐pyramidal geometry, with two cyano bridging ligands and the donor atoms of the tridentate ‘oximato’ ligand. Moreover catalytic activities of the complexes for the disproportionation of hydrogen peroxide (H2O2) were also investigated in the presence of 1H‐imidazole. The synthesized homopolynuclear CuII complexes 6 and 10 displayed eficiency in disproportion reactions of H2O2 producing H2O and dioxygen thus showing catalase‐like activity. 相似文献
10.
John S. Maass Rudy L. Luck Matthias Zeller 《Acta Crystallographica. Section C, Structural Chemistry》2012,68(8):m233-m234
The title compound, [Co2(C2H4NO)2(OH)2(C5H5N)4](ClO4)2·2C2H3N, consists of two octahedral CoIII centers arranged around an inversion point in which two cis hydroxide and two trans acetylamidate ligands link the two centers together, forming a dimeric cationic complex. Each CoIII center has two cis pyridine ligands which coordinate in the same plane as the cis hydroxide ligands. Two acetonitrile solvent molecules and two perchlorate anions are hydrogen bonded to the H atoms on the bridging hydroxide and acetylamidate (N atom) ligands, respectively. 相似文献
11.
The reaction of tricyanometallate precursor, (Bu4N)[(pzTp)Fe(CN)3] with Cu(ClO4)2·6H2O in the presence of the tetradentate ligand tris(2‐pyridylmethyl)amine (TPyA) afford the dinuclear compound fac‐{[FeIII(pzTp)(CN)2(μ‐CN)]CuII(TPA)}·Et2O·ClO4 ( 1 ) (pzTp = tetrakis(pyrazolyl)borate). The molecular structure was determined by single‐crystal X‐ray diffraction. In compound 1 , the FeIII ion is coordinated by three cyanide carbon atoms and three nitrogen atoms of pzTp anions. Whereas, the CuII ion is surrounded by one cyanide nitrogen atom and four nitrogen atoms from the TPyA ligand. Magnetic measurements indicate the intramolecular ferromagnetic coupling is observed for compound 1 , and it has S = 1 ground states. 相似文献
12.
Mark Bartholomä Dr. Sergej Gisbrecht Dipl.‐Chem. Stefan Stucky Dr. Christian Neis Dr. Bernd Morgenstern Dr. Kaspar Hegetschweiler Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(11):3326-3340
The hexadentate ligand all‐cis‐N1,N2‐bis(2,4,6‐trihydroxy‐3,5‐diaminocyclohexyl)ethane‐1,2‐diamine (Le) was synthesized in five steps with an overall yield of 39 % by using [Ni(taci)2]SO4?4 H2O as starting material (taci=1,3,5‐triamino‐1,3,5‐trideoxy‐cis‐inositol). Crystal structures of [Na0.5(H6Le)](BiCl6)2Cl0.5?4 H2O ( 1 ), [Ni(Le)]‐ Cl2?5 H2O ( 2 ), [Cu(Le)](ClO4)2?H2O ( 3 ), [Zn(Le)]CO3?7 H2O ( 4 ), [Co(Le)](ClO4)3 ( 5 c ), and [Ga(H?2Le)]‐ NO3?2 H2O ( 6 ) are reported. The Na complex 1 exhibited a chain structure with the Na+ cations bonded to three hydroxy groups of one taci subunit of the fully protonated H6(Le)6+ ligand. In 2 , 3 , 4 , and 5 c , a mononuclear hexaamine coordination was found. In the Ga complex 6 , a mononuclear hexadentate coordination was also observed, but the metal binding occurred through four amino groups and two alkoxo groups of the doubly deprotonated H?2(Le)2?. The steric strain within the molecular framework of various M(Le) isomers was analyzed by means of molecular mechanics calculations. The formation of complexes of Le with MnII, CuII, ZnII, and CdII was investigated in aqueous solution by using potentiometric and spectrophotometric titration experiments. Extended equilibrium systems comprising a large number of species were observed, such as [M(Le)]2+, protonated complexes [MHz(Le)]2+z and oligonuclear aggregates. The pKa values of H6(Le)6+ (25 °C, μ=0.10 m ) were found to be 2.99, 5.63, 6.72, 7.38, 8.37, and 9.07, and the determined formation constants (log β) of [M(Le)]2+ were 6.13(3) (MnII), 20.11(2) (CuII), 13.60(2) (ZnII), and 10.43(2) (CdII). The redox potentials (vs. NHE) of the [M(Le)]3+/2+ couples were elucidated for Co (?0.38 V) and Ni (+0.90 V) by cyclic voltammetry. 相似文献
13.
A. Gueddi B. Mernari M. Giorgi M. Pierrot 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(10):e426-e428
The reaction of the diazine ligand 3,5‐bis(2‐pyridinyl)‐1,3,4‐oxadiazole (pod, C12H8N4O), with Cu(CF3SO3)2 or Ni(ClO4)2 afforded the title complexes diaquabis[3,5‐bis(2‐pyridinyl)‐1,3,4‐oxadiazole‐N2,N3]copper(II) bis(trifluoromethanesulfonate), [Cu(pod)2(H2O)2](CF3SO3)2, and diaquabis[3,5‐bis(2‐pyridinyl)‐1,3,4‐oxadiazole‐N2,N3]nickel(II) diperchlorate, [Ni(pod)2(H2O)2](ClO4)2. Both complexes present a crystallographically centrosymmetric mononuclear cation structure which consists of a six‐coordinated CuII or NiII ion with two pod molecules acting as bidentate ligands and two axially coordinated water molecules. 相似文献
14.
Takuya Shiga Ryo Saiki Lisa Akiyama Reiji Kumai Dominik Natke Franz Renz Jamie M. Cameron Graham N. Newton Hiroki Oshio 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(17):5714-5718
A mononuclear FeII complex, prepared with a Brønsted diacid ligand, H2L (H2L=2‐[5‐phenyl‐1H‐pyrazole‐3‐yl] 6‐benzimidazole pyridine), shows switchable physical properties and was isolated in five different electronic states. The spin crossover (SCO) complex, [FeII(H2L)2](BF4)2 ( 1A ), exhibits abrupt spin transition at T1/2=258 K, and treatment with base yields a deprotonated analogue [FeII(HL)2] ( 1B ), which shows gradual SCO above 350 K. A range of FeIII analogues were also characterized. [FeIII(HL)(H2L)](BF4)Cl ( 1C ) has an S=5/2 spin state, while the deprotonated complexes [FeIII(L)(HL)], ( 1D ), and (TEA)[FeIII(L)2], ( 1E ) exist in the low‐spin S=1/2 state. The electronic properties of the five complexes were fully characterized and we demonstrate in situ switching between multiple states in both solution and the solid‐state. The versatility of this simple mononuclear system illustrates how proton donor/acceptor ligands can vastly increase the range of accessible states in switchable molecular devices. 相似文献
15.
Wei Sun Yan‐Tuan Li Zhi‐Yong Wu Ning‐Yu Xiao 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(3):m111-m113
In the crystal structure of the title complex, [Ni2(C10H20N4O2)(C12H12N2)2](ClO4)2 or [Ni(dmaeoxd)Ni(dmbp)2](ClO4)2 {H2dmaeoxd is N,N′‐bis[2‐(dimethylamino)ethyl]oxamide and dmbp is 4,4′‐dimethyl‐2,2′‐bipyridine}, the deprotonated dmaeoxd2− ligand is in a cis conformation and bridges two NiII atoms, one of which is located in a slightly distorted square‐planar environment, while the other is in an irregular octahedral environment. The cation is located on a twofold symmetry axis running through both Ni atoms. The dmaeoxd2− ligands interact with each other via C—H⋯O hydrogen bonds and π–π interactions, which results in an extended chain along the c axis. 相似文献
16.
Jia Wang Tianchao You Teng Wang Qikui Liu Jianping Ma Guoxia Jin 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(6):806-811
The adsorption behaviour of the CdII–MOF {[Cd(L)2(ClO4)2]·H2O ( 1 ), where L is 4‐amino‐3,5‐bis[3‐(pyridin‐4‐yl)phenyl]‐1,2,4‐triazole, for butan‐2‐one was investigated in a single‐crystal‐to‐single‐crystal (SCSC) fashion. A new host–guest system that encapsulated butan‐2‐one molecules, namely poly[[bis{μ3‐4‐amino‐3,5‐bis[3‐(pyridin‐4‐yl)phenyl]‐1,2,4‐triazole}cadmium(II)] bis(perchlorate) butanone sesquisolvate], {[Cd(C24H18N6)2](ClO4)2·1.5C4H8O}n, denoted C4H8O@Cd‐MOF ( 2 ), was obtained via an SCSC transformation. MOF 2 crystallizes in the tetragonal space group P43212. The specific binding sites for butan‐2‐one in the host were determined by single‐crystal X‐ray diffraction studies. N—H…O and C—H…O hydrogen‐bonding interactions and C—H…π interactions between the framework, ClO4? anions and guest molecules co‐operatively bind 1.5 butan‐2‐one molecules within the channels. The adsorption behaviour was further evidenced by 1H NMR, IR, TGA and powder X‐ray diffraction experiments, which are consistent with the single‐crystal X‐ray analysis. A 1H NMR experiment demonstrates that the supramolecular interactions between the framework, ClO4? anions and guest molecules in MOF 2 lead to a high butan‐2‐one uptake in the channel. 相似文献
17.
Kieran Griffiths Dr. Christopher W. D. Gallop Dr. Alaa Abdul‐Sada Dr. Alfredo Vargas Dr. Oscar Navarro Dr. George E. Kostakis 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(17):6358-6361
Three isoskeletal tetranuclear coordination clusters with general formula [MII2DyIII2L4(EtOH)6](ClO4)2?2 EtOH, (M=Co, 1 ; M=Ni, 2 ) and [NiII2DyIII2L4Cl2(CH3CN)2]?2 CH3CN ( 3 ), have been synthesized and characterized. These air‐stable compounds, and in particular 3 , display efficient homogeneous catalytic behavior in the room‐temperature synthesis of trans‐4,5‐diaminocyclopent‐2‐enones from 2‐furaldehyde and primary or secondary amines under a non‐inert atmosphere. 相似文献
18.
Feng Su Cheng-Yong Zhou Lin-Tao Wu Xi Wu Jing Su Chun Han Zhi-Jun Wang 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(8):1073-1083
Two CoII‐based coordination polymers, namely poly[(μ4‐biphenyl‐2,2′,5,5′‐tetracarboxylato){μ2‐1,3‐bis[(1H‐imidazol‐1‐yl)methyl]benzene}dicobalt(II)], [Co2(C16H6O8)(C14H14N4)2]n or [Co2(o,m‐bpta)(1,3‐bimb)2]n ( I ), and poly[[aqua(μ4‐biphenyl‐2,2′,5,5′‐tetracarboxylato){1,4‐bis[(1H‐imidazol‐1‐yl)methyl]benzene}dicobalt(II)] dihydrate], {[Co2(C16H6O8)(C14H14N4)2(H2O)2]·4H2O}n or {[Co2(o,m‐bpta)(1,4‐bimb)2(H2O)2]·4H2O}n ( II ), were synthesized from a mixture of biphenyl‐2,2′,5,5′‐tetracarboxylic acid, i.e. [H4(o,m‐bpta)], CoCl2·6H2O and N‐donor ligands under solvothermal conditions. The complexes were characterized by IR spectroscopy, elemental analysis, single‐crystal X‐ray diffraction and powder X‐ray diffraction analysis. The bridging (o,m‐bpta)4? ligands combine with CoII ions in different μ4‐coordination modes, leading to the formation of one‐dimensional chains. The central CoII atoms display tetrahedral [CoN2O2] and octahedral [CoN2O4] geometries in I and II , respectively. The bis[(1H‐imidazol‐1‐yl)methyl]benzene (bimb) ligands adopt trans or cis conformations to connect CoII ions, thus forming two three‐dimensional (3D) networks. Complex I shows a (2,4)‐connected 3D network with left‐ and right‐handed helical chains constructed by (o,m‐bpta)4? ligands. Complex II is a (4,4)‐connected 3D novel network with ribbon‐like chains formed by (o,m‐bpta)4? linkers. Magnetic studies indicate an orbital contribution to the magnetic moment of I and II due to the longer Co…Co distances. An attempt has been made to fit the χMT results to the magnetic formulae for mononuclear CoII complexes, the fitting indicating the presence of weak antiferromagnetic interactions between the CoII ions. 相似文献
19.
Prof. Biing‐Chiau Tzeng Tsung‐Yi Chang Sheng‐Luen Wei Dr. Hwo‐Shuenn Sheu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(16):5105-5112
A 1D double‐zigzag framework, {[Zn(paps)2(H2O)2](ClO4)2}n ( 1 ; paps=N,N′‐bis(pyridylcarbonyl)‐4,4′‐diaminodiphenyl thioether), was synthesized by the reaction of Zn(ClO4)2 with paps. However, a similar reaction, except that dry solvents were used, led to the formation of a novel 2D polyrotaxane framework, [Zn(paps)2(ClO4)2]n ( 2 ). This difference relies on the fact that water coordinates to the ZnII ion in 1 , but ClO4? ion coordination is found in 2 . Notably, the structures can be interconverted by heating and grinding in the presence of moisture, and such a structural transformation can also be proven experimentally by powder and single‐crystal X‐ray diffraction studies. The related N,N′‐bis‐ (pyridylcarbonyl)‐4,4′‐diaminodiphenyl ether (papo) and N,N′‐(methylenedi‐para‐phenylene)bispyridine‐4‐carboxamide (papc) ligands were reacted with ZnII ions as well. When a similar reaction was performed with dry solvents, except that papo was used instead of paps, the product mixture contained mononuclear [Zn(papo)(CH3OH)4](ClO4)2 ( 5 ) and the polyrotaxane [Zn(papo)2(ClO4)2]n ( 4 ). From the powder XRD data, grinding this mixture in the presence of moisture resulted in total conversion to the pure double‐zigzag {[Zn(papo)2(H2O)2](ClO4)2}n ( 3 ) immediately. Upon heating 3 , the polyrotaxane framework of 4 was recovered. The double‐zigzag {[Zn(papc)2(H2O)2](ClO4)2}n ( 6 ) and polyrotaxane [Zn(papc)2(ClO4)2]n ( 7 ) were synthesized in a similar reaction. Although upon heating the double‐zigzag 6 undergoes structural transformation to give the polyrotaxane 7 , grinding solid 7 in the presence of moisture does not lead to the formation of 6 . Significantly, the bright emissions for double‐zigzag frameworks of 1 and 3 and weak ones for polyrotaxane frameworks of 2 and 4 also show interesting mechanochromic luminescence. 相似文献
20.
Jesús Martínez Rufina Bastida Alejandro Macías Laura Valencia Manuel Vicente 《无机化学与普通化学杂志》2005,631(11):2046-2053
The pendant‐armed ligands L1 and L2 were synthesized by N‐alkylation of the four secondary amine groups of the macrocyclic precursor L using o‐nitrobenzylbromide (L1) and p‐nitrobenzylbromide (L2). Nitrates and perchlorates of CuII, NiII and CoII were used to synthesize the metal complexes of both ligands and the complexes were characterized by microanalysis, MS‐FAB, conductivity measurements, IR and UV‐Vis spectroscopy and magnetic studies. The crystal structures of L1, [CuL1](ClO4)2·CH3CN·H2O, [CuL2](ClO4)2·6CH3CN, [CuL2][Cu(NO3)4]·5CH3CN·0.5CH3OH and [NiL2](ClO4)2·3CH3CN·H2O were determined by single crystal X‐ray crystallography. These structural analysis reveal the free ligand L1, three mononuclear endomacrocyclic complexes {[CuL1](ClO4)2·CH3CN·H2O, [CuL2](ClO4)2·6CH3CN and [NiL2](ClO4)2·3CH3CN·H2O} and one binuclear complex {[CuL2][Cu(NO3)4]·5CH3CN·0.5CH3OH} in which one of the metals is in the macrocyclic framework and the other metal is outside the ligand cavity and coordinated to four nitrate ions. 相似文献