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1.
Dr. Marcello Gennari Bertrand Gerey Dr. Nikita Hall Dr. Jacques Pécaut Dr. Marie‐Noëlle Collomb Mathieu Rouzières Dr. Rodolphe Clérac Dr. Maylis Orio Dr. Carole Duboc 《Angewandte Chemie (International ed. in English)》2014,53(21):5318-5321
Disulfide/thiolate interconversion supported by transition‐metal ions is proposed to be implicated in fundamental biological processes, such as the transport of metal ions or the regulation of the production of reactive oxygen species. We report herein a mononuclear dithiolate CoIII complex, [CoIIILS(Cl)] ( 1 ; LS=sulfur containing ligand), that undergoes a clean, fast, quantitative and reversible CoII disulfide/CoIII thiolate interconversion mediated by a chloride anion. The removal of Cl? from the CoIII complex leads to the formation of a bis(μ‐thiolato) μ‐disulfido dicobalt(II) complex, [Co2II,IILSSL]2+ ( 2 2+). The structures of both complexes have been resolved by single‐crystal X‐ray diffraction; their magnetic, spectroscopic, and redox properties investigated together with DFT calculations. This system is a unique example of metal‐based switchable Mn2‐RSSR/2 M(n+1)‐SR (M=metal ion, n=oxidation state) system that does not contain copper, acts under aerobic conditions, and involves systems with different nuclearities. 相似文献
2.
Prof. Dr. Hitoshi Miyasaka Tomokura Madanbashi Ayumi Saitoh Dr. Natsuko Motokawa Ryuta Ishikawa Prof. Dr. Masahiro Yamashita Dr. Stefan Bahr Prof. Dr. Wolfgang Wernsdorfer Dr. Rodolphe Clérac 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(13):3942-3954
A series of isostructural cyano‐bridged MnIII(h.s.)–MIII(l.s.) alternating chains, [MnIII(5‐TMAMsalen)MIII(CN)6] ? 4H2O (5‐TMAMsalen2?=N,N′‐ethylenebis(5‐trimethylammoniomethylsalicylideneiminate), MnIII(h.s.)=high‐spin MnIII, MIII(l.s.)=low‐spin CoIII, Mn? Co ; FeIII, Mn? Fe ; MnIII, Mn? Mn ; CrIII, Mn? Cr ) was synthesized by assembling [MnIII(5‐TMAMsalen)]3+ and [MIII(CN)6]3?. The chains present in the four compounds, which crystallize in the monoclinic space group C2/c, are composed of an [‐MnIII‐NC‐MIII‐CN‐] repeating motif, for which the ‐NC‐MIII‐CN‐ motif is provided by the [MIII(CN)6]3? moiety adopting a trans bridging mode between [MnIII(5‐TMAMsalen)]3+ cations. The MnIII and MIII ions occupy special crystallographic positions: a C2 axis and an inversion center, respectively, forming a highly symmetrical chain with only one kind of cyano bridge. The Jahn–Teller axis of the MnIII(h.s.) ion is perpendicular to the N2O2 plane formed by the 5‐TMAMsalen tetradentate ligand. These Jahn–Teller axes are all perfectly aligned along the unique chain direction without a bending angle, although the chains are corrugated with an Mn‐Naxis‐C angle of about 144°. In the crystal structures, the chains are well separated with the nearest inter‐chain M???M distance being relatively large at 9 Å due to steric hindrance of the bulky trimethylammoniomethyl groups of the 5‐TMAMsalen ligand. The magnetic properties of these compounds have been thoroughly studied. Mn? Fe and Mn? Mn display intra‐chain ferromagnetic interactions, whereas Mn? Cr is characterized by an antiferromagnetic exchange that induces a ferrimagnetic spin arrangement along the chain. Detailed analyses of both static and dynamic magnetic properties have demonstrated without ambiguity the single‐chain magnet (SCM) behavior of these three systems, whereas Mn? Co is merely paramagnetic with SMn=2 and D/kB=?5.3 K (D being a zero‐field splitting parameter). At low temperatures, the Mn? M compounds with M=Fe, Mn, and Cr display remarkably large M versus H hysteresis loops for applied magnetic fields along the easy magnetic direction that corresponds to the chain direction. The temperature dependence of the associated relaxation time for this series of compounds systematically exhibits a crossover between two Arrhenius laws corresponding to infinite‐chain and finite‐chain regimes for the SCM behavior. These isostructural hetero‐spin SCMs offer a unique series of alternating [‐Mn‐NC‐M‐CN‐] chains, enabling physicists to test theoretical SCM models between the Ising and Heisenberg limits. 相似文献
3.
Developing Intense Blue and Magenta Colors in α‐LiZnBO3: The Role of 3d‐Metal Substitution and Coordination
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S. Tamilarasan Prof. Dr. M. L. P. Reddy Prof. Dr. S. Natarajan Prof. Dr. J. Gopalakrishnan 《化学:亚洲杂志》2016,11(22):3234-3240
We describe the synthesis, crystal structures, and optical absorption spectra/colors of 3d‐transition‐metal‐substituted α‐LiZnBO3 derivatives: α‐LiZn1?xMIIxBO3 (MII=CoII (0<x<0.50), NiII (0<x≤0.05), CuII (0<x≤0.10)) and α‐Li1+xZn1?2xMIIIxBO3 (MIII=MnIII (0<x≤0.10), FeIII (0<x≤0.25)). The crystal structure of the host α‐LiZnBO3, which is both disordered and distorted with respect to Li and Zn occupancies and coordination geometries, is largely retained in the derivatives, which gives rise to unique colors (blue for CoII, magenta for NiII, violet for CuII) that could be of significance for the development of new, inexpensive, and environmentally friendly pigment materials, particularly in the case of the blue pigments. Accordingly, this work identifies distorted tetrahedral MO4 (M=Co, Ni, Cu) structural units, with a long M?O bond that results in trigonal bipyramidal geometry, as new chromophores for blue, magenta, and violet colors in a α‐LiZnBO3 host. From the L*a*b* color coordinates, we found that Co‐substituted compounds have an intense blue color that is stronger than that of CoAl2O4 and YIn0.90Mn0.10O3. The near‐infrared (NIR) reflectance spectral studies indicate that these compounds exhibit a moderate IR reflectivity that could be significant for applications as “cool pigments”. 相似文献
4.
Mitsumoto K Oshiro E Nishikawa H Shiga T Yamamura Y Saito K Oshio H 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(35):9612-9618
Cyanide‐bridged metal complexes of [Fe8M6(μ‐CN)14(CN)10 (tp)8(HL)10(CH3CN)2][PF6]4?n CH3CN?m H2O (HL=3‐(2‐pyridyl)‐5‐[4‐(diphenylamino)phenyl]‐1H‐pyrazole), tp?=hydrotris(pyrazolylborate), 1 : M=Ni with n=11 and m=7, and 2 : M=Co with n=14 and m=5) were prepared. Complexes 1 and 2 are isomorphous, and crystallized in the monoclinic space group P21/n. They have tetradecanuclear cores composed of eight low‐spin (LS) FeIII and six high‐spin (HS) MII ions (M=Ni and Co), all of which are bridged by cyanide ions, to form a crown‐like core structure. Magnetic susceptibility measurements revealed that intramolecular ferro‐ and antiferromagnetic interactions are operative in 1 and in a fresh sample of 2 , respectively. Ac magnetic susceptibility measurements of 1 showed frequency‐dependent in‐ and out‐of‐phase signals, characteristic of single‐molecule magnetism (SMM), while desolvated samples of 2 showed thermal‐ and photoinduced intramolecular electron‐transfer‐coupled spin transition (ETCST) between the [(LS‐FeII)3(LS‐FeIII)5(HS‐CoII)3(LS‐CoIII)3] and the [(LS‐FeIII)8(HS‐CoII)6] states. 相似文献
5.
N. A. Sanina G. V. Shilov N. S. Ovanesyan L. O. Atovmyan 《Russian Chemical Bulletin》1999,48(8):1581-1583
Bimetallic oxalate-bridged complexes Q[MIICo(C2O4)3] (Q=Me4N+, Bun 4P+; MII=Mn, Co, Ni, Cu, Zn) were synthesized. Single crystals of [NBun 4][MnIICoIII(C2O4)3] were studied by XRD. Unit cell parametersa=b=9.242(3) Å,c=54.524(13) Å; space groupR3c. Magnetic measurements indicate the absence of a magnetic phase transition up to the temperature of liquid helium. The XRD data confirm the presence of CoIII ions with a low-spin configuration in the crystal. 相似文献
6.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(28):8323-8327
This study deals with the unprecedented reactivity of dinuclear non‐heme MnII–thiolate complexes with O2, which dependent on the protonation state of the initial MnII dimer selectively generates either a di‐μ‐oxo or μ‐oxo‐μ‐hydroxo MnIV complex. Both dimers have been characterized by different techniques including single‐crystal X‐ray diffraction and mass spectrometry. Oxygenation reactions carried out with labeled 18O2 unambiguously show that the oxygen atoms present in the MnIV dimers originate from O2. Based on experimental observations and DFT calculations, evidence is provided that these MnIV species comproportionate with a MnII precursor to yield μ‐oxo and/or μ‐hydroxo MnIII dimers. Our work highlights the delicate balance of reaction conditions to control the synthesis of non‐heme high‐valent μ‐oxo and μ‐hydroxo Mn species from MnII precursors and O2. 相似文献
7.
The Crystal Structure of the Hydrated Cyano Complexes NMe4MnII[(Mn, Cr)III(CN)6] · 3 H2O and NMe4Cd[MIII(CN)6] · 3 H2O (MIII = Fe, Co): Compounds Related to Prussian Blue The crystal structures of the isotypic tetragonal compounds (space group I4, Z = 10) NMe4MnII · [(Mn, Cr)III(CN)6] · 3 H2O (a = 1653.2(4), c = 1728.8(6) pm), NMe4Cd[Fe(CN)6] · 3 H2O (a = 1642.7(1), c = 1733.1(1) pm) and NMe4Cd[Co(CN)6] · 3 H2O (a = 1632.1(2), c = 1722.4(3) pm) were determined by X‐rays. They exhibit ⊥ c cyanobridged layers of octahedra [MIII(CN)6] and [MIIN4(OH2)2], which punctually are interconnected also || c to yield altogether a spaceous framework. The MII atoms at the positions linking into the third dimension are only five‐coordinated and form square pyramids [MIIN5] with angles N–MII–N near 104° and distances of Mn–N: 1 × 214, 4 × 219 pm; Cd–N: 1 × 220 resp. 222, 4 × 226 resp. 228 pm. Further details and structural relations within the family of Prussian Blue are reported and discussed. 相似文献
8.
The electrochemical and spectroscopic properties of [Mn2(tpp)2(SO4)] (H2tpp=tetraphenylporphyrin=5,10,15,20‐tetraphenyl‐21H,23H‐porphine) were studied to characterize the stability of this compound as a function of solvent, redox state, and sulfate concentration. In non‐coordinating solvents such as 1,2‐dichloroethane, the dimer was stable, and two cyclic voltammetric waves were observed in the region for MnIII reduction. These waves correspond to reduction of the dimer to [MnII(tpp)] and [MnIII(tpp)(OSO3)]?, and reduction of [MnIII(tpp)(OSO3)]? to [MnII(tpp)(OSO3)]2?, respectively. In the coordinating solvent DMSO, [Mn2(tpp)2(SO4)] was unstable and dissociated to form [MnIII(tpp)(DMSO)2]+. A single voltammetric wave was observed for MnIII reduction in this solvent, corresponding to formation of [MnII(tpp)(DMSO)]. In non‐coordinating solvent systems, addition of sulfate (as the bis(triphenylphosphoranylidene)ammonium (PPN+) salt) resulted in dimer dissociation, yielding [MnIII(tpp)(OSO3)]?. Reduction of this monomer produced [MnII(tpp)(OSO3)]2?. In DMSO, addition of SO led to displacement of solvent molecules forming [MnIII(tpp)(OSO3)]?. Reduction of this species in DMSO led to [MnII(tpp)(DMSO)]. 相似文献
9.
Ferrando-Soria J Pardo E Ruiz-García R Cano J Lloret F Julve M Journaux Y Pasán J Ruiz-Pérez C 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(7):2176-2188
A series of neutral oxamato‐bridged heterobimetallic chains of general formula [MCu(Lx)2(S)2] ? p S ? q H2O [p=0–1, q=0–2.5; L1=N‐2,6‐dimethylphenyloxamate, S=DMF with M=Mn ( 1 a ) and Co ( 1 b ); L2=N‐2,6‐diethylphenyloxamate, S=DMF with M=Mn ( 2 a ) and Co ( 2 b ) or S=DMSO with M=Mn ( 2 c ) and Co ( 2 d ); L3=N‐2,6‐diisopropylphenyloxamate, S=DMF with M=Mn ( 3 a ) and Co ( 3 b ) or S=DMSO with M=Mn ( 3 c ) and Co ( 3 d )] were prepared by treating the corresponding anionic oxamatocopper(II) complexes [Cu(Lx)2]2? (x=1–3) with M2+ cations (M=Mn and Co) in DMF or DMSO as the solvent. The single‐crystal X‐ray structures of 2 a and 3 a reveal the occurrence of well‐isolated, zigzag, oxamato‐bridged manganese(II)–copper(II) chains. The intrachain Cu ??? Mn distances across the oxamato bridge are 5.3761(7) and 5.4002(17) Å for 2 a and 3 a , respectively, whereas the shortest interchain Mn ??? Mn distances are 9.4475(16) and 8.1649(14) Å for 2 a and 3 a , respectively. All of these MIICuII chains (M=Mn and Co) exhibit 1D ferrimagnetic behaviour with moderately strong intrachain antiferromagnetic coupling between the square‐planar CuII and octahedral high‐spin MII ions across the oxamato bridge [?J=31.4–35.2 and 33.4–44.8 cm?1, respectively; H =∑i?J S M,i( S Cu,i+ S Cu,i?1)]. Only the CoIICuII chains show slow magnetic relaxation effects characteristic of single‐chain magnets (SCMs). Analysis of the magnetic relaxation dynamics of 3 d shows a thermally activated mechanism (Arrhenius law dependence) with values of the pre‐exponential factor (τ0=2.6×10?9 s) and activation energy (Ea=7.7 cm?1) that are typical of SCMs. In contrast, two relaxation regimes are observed for 2 d in different temperature regions (τ0=3.2×10?10 s and Ea=24.7 cm?1 for T<4.5 K and τ0=3.2×10?14 s and Ea=37.5 cm?1 for T>4.5 K). 相似文献
10.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(26):7771-7776
It is a challenge to reversibly switch both magnetism and polarity using light irradiation. Herein we report a linear Fe2Co complex, whereby interconversion between FeIIILS(μ‐CN)CoIIHS(μ‐NC)FeIIILS (LS=low‐spin, HS=high‐spin) and FeIIILS(μ‐CN)CoIIILS(μ‐NC)FeIILS linkages could be achieved upon heating and cooling, or alternating laser irradiation at 808 and 532 nm. The electron spin arrangement and charge distribution were simultaneously tuned accompanying bidirectional metal‐to‐metal charge transfer, providing switchable polarity and magnetism in the complex. 相似文献
11.
Vadithala Ramakrishna Rao Korandla Goverdhan Reddy Utukuri Venkata Seshaiah Vuppalapati Jayathyagaraju 《Transition Metal Chemistry》1993,18(3):258-261
Summary
N-salicylidene anthranilamide (H2SAA) and its CrIII, MnII, FeIII, CoII, NiII and CuII complexes were prepared and characterized by physicochemical and spectroscopic data. H2SAA enolizes to give a dibasic ONO donor set in the divalent metal complexes. It also binds to the trivalent metal ions in a nonenolized form using a monobasic ONN donor set. CoII is oxidized to CoIII during complexation. Octahedral geometries are proposed for CrIII, MnII, FeIII and CoIII complexes, while square planar geometries are suggested for the NiII and CuII complexes. Phenoxide bridging in the CrIII and FeIII complexes and enoxide bridging in the NiII and CuII complexes is proposed. 相似文献
12.
V. Kaiser A. Le Lirzin J. Darriet A. Tressaud H. Holler D. Babel 《无机化学与普通化学杂志》2002,628(12):2617-2624
Structural Studies with Usovites: Ba2CaMIIV2F14 (MIII = Mn, Fe), Ba2CaMnFe2F14 and Ba2CaCuM2IIIF14 (MIII = Mn, Fe, Ga). Single crystals of six compounds Ba2CaMIIM2IIIF14 were prepared to refine their usovite type structure (space group C2/c, Z = 4) using X‐ray diffractometer data. The cell parameters of the phases studied with MIIM2III= MnV2, FeV2, CuMn2, MnFe2, CuFe2 und CuGa2 are within the range 1374≤a/pm≤1384, 534≤b/pm≤542, 1474≤c/pm≤1510, 91, 3≤ß/°≤93, 2. The atoms Ca and MII are incompletely ordered on the 8‐ and 6‐coordinated positions, 4e and 4b, respectively. In the case of Ba2CaFeV2F14 and Ba2CaCuGa2F14 there is reciprocal substitution (x≈0, 1): (Ca1‐xMxII) (4e) and (M1‐xIICax) (4b). In the case of the other usovites Ca‐enriched phases Ba2Ca(M1‐yIICay)M2IIIF14 occured (up to y≈0, 35), exhibiting partial substitution at the octahedral position (4b) only, showing a corresponding increase in MII‐F distances. The distortion of [MIIF6] and [MIIIF6] octahedra within the structure is considerably enhanced on replacement by CuII and MnIII. The results of powder magnetic susceptibility measurements of Ba2CaMnV2F14 and Ba2CaFeV2F14 (TN≈7K) are reported. 相似文献
13.
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
14.
Damir A. Safin Dr. Maria G. Babashkina Felix D. Sokolov Sergey V. Baranov F. Ekkehardt Hahn Tania Pape 《无机化学与普通化学杂志》2009,635(11):1613-1619
The reaction of the potassium salts of N‐phosphorylated thioureas [4′‐benzo‐15‐crown‐5]NHC(S)NHP(Y)(OiPr)2 (Y = S, HLI ; Y = O, HLII ) with ZnII and CoII cations in aqueous EtOH leads to complexes of formulae Zn(LI,II‐S,Y)2 (Y = S, 1 ; Y = O, 2 ) and Co(LI‐S,S′)2 ( 3 ), while interaction of the potassium salt of N‐phosphorylated thioamide [4′‐benzo‐15‐crown‐5]C(S)NHP(O)(OiPr)2 ( HLIII ) with ZnII in the same conditions leads to the complex Zn(HLIII)(LIII‐S,O)2 ( 4 ). The reaction of the potassium salt of crown ether‐containing N‐phosphorylated bis‐thiourea N,N′‐[C(S)NHP(O)(OiPr)2]2‐1,10‐diaza‐18‐crown‐6 ( H2L ) with CoII, ZnII and PdII cations in anhydrous CH3OH leads to complexes M2(L‐O,S)2 (M = Co, 5 ; Zn, 6 ; M = Pd, 7 ). Thioamide HLIII was investigated by single‐crystal X‐ray diffraction. 相似文献
15.
Mimicking Class I b Mn2‐Ribonucleotide Reductase: A MnII2 Complex and Its Reaction with Superoxide
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Adriana M. Magherusan Ang Zhou Erik R. Farquhar Max García‐Melchor Brendan Twamley Lawrence Que Jr. Aidan R. McDonald 《Angewandte Chemie (International ed. in English)》2018,57(4):918-922
A fascinating discovery in the chemistry of ribonucleotide reductases (RNRs) has been the identification of a dimanganese (Mn2) active site in class I b RNRs that requires superoxide anion (O2.?), rather than dioxygen (O2), to access a high‐valent Mn2 oxidant. Complex 1 ([Mn2(O2CCH3)(N‐Et‐HPTB)](ClO4)2, N‐Et‐HPTB=N,N,N′,N′‐tetrakis(2‐(1‐ethylbenzimidazolyl))‐2‐hydroxy‐1,3‐diaminopropane) was synthesised in high yield (90 %). 1 was reacted with O2.? at ?40 °C resulting in the formation of a metastable species ( 2 ). 2 displayed electronic absorption features (λmax=460, 610 nm) typical of a Mn‐peroxide species and a 29‐line EPR signal typical of a MnIIMnIII entity. Mn K‐edge X‐ray absorption near‐edge spectroscopy (XANES) suggested a formal oxidation state change of MnII2 in 1 to MnIIMnIII for 2 . Electrospray ionisation mass spectrometry (ESI‐MS) suggested 2 to be a MnIIMnIII‐peroxide complex. 2 was capable of oxidizing ferrocene and weak O?H bonds upon activation with proton donors. Our findings provide support for the postulated mechanism of O2.? activation at class I b Mn2 RNRs. 相似文献
16.
Tao Liu Bing‐Wu Wang Yi‐Hong Chen Zhe‐Ming Wang Prof. Song Gao Prof. 《无机化学与普通化学杂志》2008,634(4):778-783
Two mixed‐valent disc‐like hepta‐nuclear compounds of [FeIIFeIII6(tea)6](ClO4)2 ( 1Fe , tea = N(CH2CH2O)33?) and [MnII3MnIII4(nmdea)6(N3)6]·CH3OH ( 2Mn , nmdea = CH3N(CH2CH2O)22?) have been synthesized by the reaction of Fe(ClO4)2·6H2O with triethanolamine (H3tea) for the former and reaction of Mn(ClO4)2·6H2O with diethanolamine (H2nmdea) and NaN3 for the later, respectively. 1Fe has the cationic cluster with a planar [FeIIFeIII6] core consisting of one central FeII and six rim FeIII atoms in hexagonal arrangement. The Fe ions are linked by the oxo‐bridges from the alcohol arms in the manner of edge‐sharing of their coordination octahedra. 2Mn is a neutral cluster with a [MnII3MnIII4] core possessing one central MnII atom surrounded by six rim Mn ions, two MnII and four MnIII. The structure is similar to 1Fe but involves six terminal azido ligands, each coordinate one rim Mn ion. 1Fe showed dominant antiferromagnetic interaction within the cluster and long‐range ordering at 2.7 K. The cluster probably has a ground state of low spin of S = 5/2 or 4/2. The long‐range ordering is weak ferromagnetic, showing small hysteresis with a remnant magnetization of 0.3 Nβ and a coercive field of 40 Oe. Moreover, the isofield of lines 1Fe are far from superposition, indicating the presence of significant zero–field splitting. Ferromagnetic interactions are dominant in 2Mn . An intermediate spin ground state 25/2 is observed at low field. In high field of 50 kOe, the energetically lowest state is given by the ms = 31/2 component of the S = 31/2 multiplet due to the Zeeman effect. Despite of the large ground state, no single‐molecule magnet behavior was found above 2 K. 相似文献
17.
Low Spin Manganese Phthalocyanines: Preparation, Properties and Electronic Raman Spectrum of Di(cyano)phthalocyaninatomanganate(III) and -(II) . Iodophthalocyaninatomanganese(III) reacts with cyanide in acetone to yield di(cyano)phthalocyaninatomanganate(II), in dichloromethane, however di(cyano)phthalocyaninatomanganate(III) is formed. Both complexes are isolated as (n-Bu4N)-salts. In the cyclovoltammogram the redox couple MnII/MnIII is attributed to E1/2 = - 0.22 V and the first ringoxidation Pc(2 -)/Pc(1 -) to E1/2 = 0.75 V. The paramagnetic salts have magnetic moments (μeff = 2.11 resp. 2.95 B.M.) typical for the low spin ground state of MnII resp. MnIII (S = 1/2 resp. 1). The uv-vis-nir spectra are discussed. Comparison with the dicyano-complexes of CrIII, FeII/III and CoIII indicates that the multiple “extra bands” between 4 and 23 kK should be assigned to spin allowed trip-multiplets. The vibrational spectra are discussed. νas(Mn? C)(a2u) is found at 350 cm?1, νas(C? N)(a2u; cyanide) at 2 092 (MnII) and 2 114 cm?1 (MnIII). The Raman spectra are dominated by resonance Raman(RR) effects. With variable-wavelength excitation polarized, depolarized and anomalously polarized vibrations assigned to phthalocyanine skeletal modes are selectively RR-enhanced for the MnII complex. Intensive lines between 1 650 and 3 300 cm?1 are due to combinations and overtones of the a2g vibrations at 1 492 and 1 602 cm?1. In the 10 K Raman spectrum of (n-Bu4N)[Mn(CN)2Pc(2 -)] intraconfigurational transitions Γ1 → Γ4 and Γ1 → Γ3, Γ5 resulting from the splitting of the 3T1g ground state of MnIII (Oh symmetry) by spin-orbit coupling are observed as anomalously polarized and depolarized lines at 172 and 287 cm?1. 相似文献
18.
Mihaela‐Diana Şerb Manfred Speldrich Prof. Dr. Heiko Lueken Prof. Dr. Ulli Englert 《无机化学与普通化学杂志》2011,637(5):536-542
The crystal structures of two new isomorphous transition metal squarato complexes [MII(C4O4)(dmso)2(OH2)2] [MII = CoII (3d7), MnII (3d5); dmso = dimethylsulfoxide] and their magnetic properties are reported. The compounds feature two symmetrically independent chains, in which 1,3‐bridging squarato ligands connect cations in distorted octahedral surroundings of pseudo‐symmetry D4h. From an equimolar solution of CoCl2 · 6H2O and MnCl2 · 2H2O a mixed‐metal coordination polymer crystallizes; it represents a solid solution and adopts the same structure as the corresponding monometallic compounds. The results of the diffraction experiment unambiguously proof the presence of both CoII and MnII cations in either independent site albeit no precise ratio between the metal cations involved may be deduced from these findings. The difference in the magnetic properties between CoII and MnII cations in the given ligand field has allowed us to establish their ratio in the solid solution more reliably than by X‐ray diffraction: Accounting for ligand field potential and spin‐orbit coupling of CoII and regarding MnII as a pure spin system, the calculations yielded a fraction of 73 % CoII in the mixed‐metal polymer. With respect to superexchange effects only weak antiferromagnetic interactions have been detected for the three coordination polymers. 相似文献
19.
Sourav Adak Luke L. Daemen Monika Hartl Darrick Williams Jennifer Summerhill Heinz Nakotte 《Journal of solid state chemistry》2011,184(11):2854-2861
We present a comprehensive study of the structural properties and the thermal expansion behavior of 17 different Prussian Blue Analogs (PBAs) with compositions MII3[(M′)III(CN)6]2·nH2O and MII2[FeII(CN)6]·nH2O, where MII=Mn, Fe, Co, Ni, Cu and Zn, (M′)III=Co, Fe and n is the number of water molecules, which range from 5 to 18 for these compounds. The PBAs were synthesized via standard chemical precipitation methods, and temperature-dependent X-ray diffraction studies were performed in the temperature range between −150 °C (123 K) and room-temperature. The vast majority of the studied PBAs were found to crystallize in cubic structures of space groups Fm3?m, F4?3m and Pm3?m. The temperature dependence of the lattice parameters was taken to compute an average coefficient of linear thermal expansion in the studied temperature range. Of the 17 compounds, 9 display negative values for the average coefficient of linear thermal expansion, which can be as large as 39.7×10−6 K−1 for Co3[Co(CN)6]2·12H2O. All of the MII3[CoIII(CN)6]2·nH2O compounds show negative thermal expansion behavior, which correlates with the Irving–Williams series for metal complex stability. The thermal expansion behavior for the PBAs of the MII3[FeIII(CN)6]2·nH2O family are found to switch between positive (for M=Mn, Co, Ni) and negative (M=Cu, Zn) behavior, depending on the choice of the metal cation (M). On the other hand, all of the MII2[FeII(CN)6]·nH2O compounds show positive thermal expansion behavior. 相似文献
20.
Sophie Romain Dr. Carole Duboc Dr. Frank Neese Prof. Eric Rivière Dr. Lyall R. Hanton Dr. Allan G. Blackman Dr. Christian Philouze Dr. Jean‐Claude Leprêtre Prof. Alain Deronzier Dr. Marie‐Noëlle Collomb Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(4):980-988
The mononuclear manganese bis‐terpyridine complex [Mn(tolyl‐terpy)2](X)3 ( 1 (X)3; X=BF4, ClO4, PF6; tolyl‐terpy=4′‐(4‐methylphenyl)‐2,2′:6′,2“‐terpyridine), containing Mn in the unusual +III oxidation state, has been isolated and characterised. The 1 3+ ion is a rare example of a mononuclear MnIII complex stabilised solely by neutral N ligands. Complex 1 3+ is obtained by electrochemical oxidation of the corresponding MnII compound 1 2+ in anhydrous acetonitrile. Under these conditions the cyclic voltammogram of 1 2+ exhibits not only the well‐known MnII/MnIII oxidation at E1/2=+0.91 V versus Ag/Ag+ (+1.21 V vs. SCE) but also a second metal‐based oxidation process corresponding to MnIII/MnIV at E1/2=+1.63 V (+1.93 V vs. SCE). Single crystals of 1 (PF6)3?2 CH3CN were obtained by an electrocrystallisation procedure. X‐ray analysis unambiguously revealed its tetragonally compressed octahedral geometry and high‐spin character. The electronic properties of 1 3+ were investigated in detail by magnetic measurements and theoretical calculations, from which a D value of +4.82 cm?1 was precisely determined. Density functional and complete active space self consistent field ab initio calculations both correctly predict a positive sign of D, in agreement with the compressed tetragonal distortion observed in the X‐ray structure of 1 (PF6)3?2 CH3CN. The different contributions to D were calculated, and the results show that 1) the spin–orbit coupling part (+2.593 cm?1) is predominant compared to the spin–spin interaction (+1.075 cm?1) and 2) the excited triplet states make the dominant contribution to the total D value. 相似文献