共查询到20条相似文献,搜索用时 206 毫秒
1.
《Journal of Coordination Chemistry》2012,65(3-4):343-353
Abstract A series of complexes of formula [(NC)5FeII—NC—FeII(CN)4L]n?, with L = H2O, pyridine, isonicotinamide and 4-cyanopyridine were prepared in aqueous solution by substitution of the corresponding [FeII(CN)5L]n? ions into [FeII(CN)5H2O]3?. The mixed valent (II, III) and fully oxidized (III, III) complexes were also obtained. The (II, II) complexes were moderately stable toward dissociation into the mononuclear species, but the mixed-valent ions were properly characterized by UV-vis-NIR spectroscopy and electrochemistry. Distinctive intervalence (IV) bands were assigned in the NIR region, with the energy being dependent on the binding properties of L; the IV band energy also correlated with the redox potential at the [NC—Fe(CN)4L] fragment. By application of the Hush model, a valence-trapped situation was found for the [(NC)5FeIII—NC—FeII(CN)4L]n? ions. The class II behavior shows, however, a value of H ab, the electronic coupling factor, of ca. 1600cm?1, indicating a moderate-to-strong communication between the metal centers. 相似文献
2.
The catalytic systems [(BPMEN)FeII(CH3CN)2](ClO4)2/H2O2/CH3OOH and [(TPA)FeII(CH3CN)2](ClO4)2/H2O2/CH3OOH, where BPMEN = N,N′-dimethyl-N,N′-bis(2-pyridylmethyl)-1,2-diaminoethane and TPA = tris(2-pyridylmethyl)amine, provide selective olefin epoxidation. Proton NMR studies showed that the mononuclear iron(IV) oxo complexes [(L)FeIV=O]2+, with L = BPMEN or TPA, are present in the cited catalytic systems. These intermediates are the decomposition products of the acylperoxo complexes [(L)FeIII-O3CCH3]2+. Such a complex was observed by the 2H NMR technique at low temperatures. The [(L)FeIV=O]2+ and [(L)FeV=O]3+ oxo complexes are possible active species in the studied catalytic systems. 相似文献
3.
Marie-Noëlle Collomb-Dunand-Sauthier Alain Deronzier Raymond Ziessel 《Journal of Electroanalytical Chemistry》1993,350(1-2)
The clectrochemical behaviour of the complexes [RuII(L)(CO)2Cl2], [RuII(L)(CO)Cl3][Me4N] and [RuII(L)(CO)2(CH3CN)2][CF3SO3]2 (L = 2,2′-bipyridine or 4,4′-isopropoxycarbonyl-2,2′-bipyridine) has been investigated in CH3CN. The oxidation of [Ru(L)(CO)2Cl2] produces new complexes [RuIII(L)(CO)(CH3CN)2Cl]2+ as a consequence of the instability of the electrogenerated transient RuIII species [RuIII(L)(CO)2Cl2]+. In contrast, the oxidation of [RuII(L)(CO)Cl3][Me4N] produces the stable [RuIII(L)(CO)Cl3] complex. In contrast [RuII(L)(CO)2(CH3CN)2][CF3SO3]2 is not oxidized in the range up to the most positive potentials achievable. The reduction of [RuII(L)(CO)2Cl2] and [RuII(L)(CO)2(CH3CN)2][CF3SO3]2 results in the formation of identical dark blue strongly adherent electroactive films. These films exhibit the characteristics of a metal-metal bond dimer structure. No films are obtained on reduction of [RuII(L)(CO)Cl3][Me4N]. The effect of the substitution of the bipyridine ligand by electron-withdrawing carboxy ester groups on the electrochemical behaviour of all these complexes has also been investigated. 相似文献
4.
Heterotrimetallic Coordination Polymers: {CuIILnIIIFeIII} Chains and {NiIILnIIIFeIII} Layers: Synthesis,Crystal Structures,and Magnetic Properties 下载免费PDF全文
Dr. Maria‐Gabriela Alexandru Dr. Diana Visinescu Prof. Marius Andruh Dr. Nadia Marino Dr. Donatella Armentano Dr. Joan Cano Prof. Francesc Lloret Prof. Miguel Julve 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(14):5429-5446
The use of the [FeIII(AA)(CN)4]? complex anion as metalloligand towards the preformed [CuII(valpn)LnIII]3+ or [NiII(valpn)LnIII]3+ heterometallic complex cations (AA=2,2′‐bipyridine (bipy) and 1,10‐phenathroline (phen); H2valpn=1,3‐propanediyl‐bis(2‐iminomethylene‐6‐methoxyphenol)) allowed the preparation of two families of heterotrimetallic complexes: three isostructural 1D coordination polymers of general formula {[CuII(valpn)LnIII(H2O)3(μ‐NC)2FeIII(phen)(CN)2 {(μ‐NC)FeIII(phen)(CN)3}]NO3 ? 7 H2O}n (Ln=Gd ( 1 ), Tb ( 2 ), and Dy ( 3 )) and the trinuclear complex [CuII(valpn)LaIII(OH2)3(O2NO)(μ‐NC)FeIII(phen)(CN)3] ? NO3 ? H2O ? CH3CN ( 4 ) were obtained with the [CuII(valpn)LnIII]3+ assembling unit, whereas three isostructural heterotrimetallic 2D networks, {[NiII(valpn)LnIII(ONO2)2(H2O)(μ‐NC)3FeIII(bipy)(CN)] ? 2 H2O ? 2 CH3CN}n (Ln=Gd ( 5 ), Tb ( 6 ), and Dy ( 7 )) resulted with the related [NiII(valpn)LnIII]3+ precursor. The crystal structure of compound 4 consists of discrete heterotrimetallic complex cations, [CuII(valpn)LaIII(OH2)3(O2NO)(μ‐NC)FeIII(phen)(CN)3]+, nitrate counterions, and non‐coordinate water and acetonitrile molecules. The heteroleptic {FeIII(bipy)(CN)4} moiety in 5 – 7 acts as a tris‐monodentate ligand towards three {NiII(valpn)LnIII} binuclear nodes leading to heterotrimetallic 2D networks. The ferromagnetic interaction through the diphenoxo bridge in the CuII?LnIII ( 1 – 3 ) and NiII?LnIII ( 5 – 7 ) units, as well as through the single cyanide bridge between the FeIII and either NiII ( 5 – 7 ) or CuII ( 4 ) account for the overall ferromagnetic behavior observed in 1 – 7 . DFT‐type calculations were performed to substantiate the magnetic interactions in 1 , 4 , and 5 . Interestingly, compound 6 exhibits slow relaxation of the magnetization with maxima of the out‐of‐phase ac signals below 4.0 K in the lack of a dc field, the values of the pre‐exponential factor (τo) and energy barrier (Ea) through the Arrhenius equation being 2.0×10?12 s and 29.1 cm?1, respectively. In the case of 7 , the ferromagnetic interactions through the double phenoxo (NiII–DyIII) and single cyanide (FeIII–NiII) pathways are masked by the depopulation of the Stark levels of the DyIII ion, this feature most likely accounting for the continuous decrease of χM T upon cooling observed for this last compound. 相似文献
5.
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
6.
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
7.
Xue‐Ru Liu Cheng‐Qi Jiao Yin‐Shan Meng Hai‐Lang Zhu Wen‐Jing Jiang Wen Wen Liang Zhao Tao Liu 《无机化学与普通化学杂志》2019,645(4):428-432
Two tetranuclear cyanide‐bridged FeIII2NiII2 compounds [Ni2(L1)4Fe2(μ‐CN)4(CN)2(L2)2] · 2ClO4 · CH3OH · 4H2O ( 1 ) and [Ni2(L1)4Fe2(μ‐CN)4(CN)2(L3)2] · 2ClO4 ( 2 ) [L1 = 4,4′‐dichloro‐2,2′‐bipyridine; L2 = hydrotris(pyrazolyl)borate; L3 = tetrakis(pyrazolyl)borate] were synthesized. Magnetic measurements indicated that both two compounds showed single‐molecule magnet (SMM) behaviors with the relaxation energy barrier of Δ/kB = 68.9(8) K for 1 and 12.6(1) K for 2 . Magneto‐structural analysis indicated that the intermolecular interactions played an important part in the slow magnetic relaxation behaviors. 相似文献
8.
Karine Gorgy Marie-Noëlle Collomb Jean-Claude Leprêtre Alain Deronzier Carole Duboc-Toia Stphane Mnage Marc Fontecave 《Electrochemistry communications》2001,3(12)
A simple electrochemical procedure to tailor thin polymeric films containing the [FeII(bpy)2(CH3CN)2]2+ and/or [FeII(bpy)3]2+-like cores have been described (bpy=2,2′-bipyridine). The procedure is based on the electroreductive precipitation of soluble polymers prepared in situ in CH3CN by mixing Fe3+ ions and a bis bipyridyl ligand, (chiragen: chir). In the resulting [FeII(chir)(CH3CN)2]n2+ films, the two labile S ligands can be easily replaced by a bidentate ligand. This method has been applied with success to design a modified electrode with a supramolecular structure. 相似文献
9.
Ni3 versus Ni30: A Truncated Octahedron Metal–Organic Cage Constructed with [Ni5(CN)4]6+ Squares and Tripodal Tris‐tacn Ligands That are Large and Flexible 下载免费PDF全文
Zongyao Zhang Kunyi Zheng Prof. Dr. Tianlong Xia Prof. Dr. Lijin Xu Prof. Dr. Rui Cao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(49):17576-17580
Reactions of trinickel complex of tripodal tris‐tacn ligand N(CH2‐m‐C6H4‐CH2tacn)3 ( L , tacn=1,4,7‐triazacyclononane) in acetonitrile–methanol solution with and without phosphate led to two complexes of distinct nuclearities, [(NiIICl)3(CH3OH)3(HPO4) L ](PF6) (Ni3, 1 ) and [(NiII5(CN)4(H2O)8Cl)6 L 8]Cl30 (Ni30, 2 ). Ligand L takes upward and downward conformation in the structure of 1 and 2 , respectively. It is proposed that phosphate directs the upward conformation of Ni3 L to form 1 . In the absence of phosphate, Ni3 L assembles with cyanide ions, which are formed by Ni‐catalyzed C?CN bond cleavage of acetonitrile, to give a nano‐sized Ni30 cage. Complex 2 represents a discrete truncated octahedron cage assembled with [Ni5(CN)4]6+ squares and large and flexible triangular ligands, which is scarcely observed for self‐assembled metal‐organic cages. The magnetic properties of 1 and 2 were examined, showing intriguing magnetic properties. 相似文献
10.
Wen Wen Dr. Yin-Shan Meng Dr. Cheng-Qi Jiao Qiang Liu Hai-Lang Zhu Prof. Ya-Ming Li Prof. Hiroki Oshio Prof. Tao Liu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(38):16535-16539
It is promising and challenging to manipulate the electronic structures and functions of materials utilizing both metal-to-metal charge transfer (MMCT) and spin-crossover (SCO) to tune the valence and spin states of metal ions. Herein, a metallocyanate building block is used to link with a FeII-triazole moiety and generates a mixed-valence complex {[(Tp4-Me)FeIII(CN)3]9[FeII4(trz-ph)6]}⋅[Ph3PMe]2⋅[(Tp4-Me)FeIII(CN)3] ( 1 ; trz-ph=4-phenyl-4H-1,2,4-triazole). Moreover, MMCT occurs between FeIII and one of the FeII sites after heat treatment, resulting in the generation of a new phase, {[(Tp4-Me)FeII(CN)3][(Tp4-Me)FeIII(CN)3]8 [FeIIIFeII3(trz-ph)6]}⋅ [Ph3PMe]2⋅[(Tp4-Me)FeIII(CN)3] ( 1 a ). Structural and magnetic studies reveal that MMCT can tune the two-step SCO behavior of 1 into one-step SCO behavior of 1 a . Our work demonstrates that the integration of MMCT and SCO can provide a new alternative for manipulating functional spin-transition materials with accessible multi-electronic states. 相似文献
11.
The reactions of py‐hz ligands ( L1–L5 ) with Pb(CF3SO3)2?H2O resulted in some rare examples of discrete single‐stranded helical PbII complexes. L1 and L2 formed non‐helical mononuclear complexes [Pb L1 (CF3SO3)2]?CHCl3 and Pb L2 (CF3SO3)2][Pb L2 CF3SO3]CF3SO3?CH3CN, which reflected the high coordination number and effective saturation of PbII by the ligands. The reaction of L3 with PbII resulted in a dinuclear meso‐helicate [Pb2 L3 (CF3SO3)2Br]CF3SO3?CH3CN with a stereochemically‐active lone pair on PbII. L4 directed single‐stranded helicates with PbII, including [Pb2 L4 (CF3SO3)3]CF3SO3?CH3CN and [Pb2 L4 CF3SO3(CH3OH)2](CF3SO3)3?2 CH3OH?2 H2O. The acryloyl‐modified py‐hz ligand L5 formed helical and non‐helical complexes with PbII, including a trinuclear PbII complex [Pb3 L5 (CF3SO3)5]CF3SO3?3CH3CN?Et2O. The high denticity of the long‐stranded py‐hz ligands L4 and L5 was essential to the formation of single‐stranded helicates with PbII. 相似文献
12.
E. B. Coropceanu A. P. Rija V. I. Lozan O. A. Bologa A. A. Boldisor I. I. Bulhac V. Ch. Kravtsov P. N. Bourosh 《Russian Journal of Coordination Chemistry》2012,38(8):545-551
The complexes [Co(DioxH)2L2][SbF6] · nH2O, where DioxH is dimethylglyoxime monoanion (DioxH?) or 1,2-cyclohexanedione dioxime (NioxH?), L is aniline (An) or triphenylphosphine (PPh3), were isolated from the CoX2 · nH2O-NaSbF6-DioxH2-L system (X = F or CH3COO) in aqueous methanol. The complexes were studied by UV, IR, and NMR spectroscopy and by X-ray diffraction. The crystal structure of [Co(DH)2(An)2][SbF6] · H2O (I) and [Co(NioxH)2(PPh3)2][SbF6] (II) is stabilized by the electrostatic interactions between the Co(III) complex cations and outer-sphere fluorine-containing anions and by hydrogen bonds between structural units. 相似文献
13.
Clemens Taube Dr. Kai Schwedtmann Medena Noikham Prof. Dr. Ekasith Somsook Dr. Felix Hennersdorf Prof. Dr. Robert Wolf Prof. Dr. Jan J. Weigand 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(9):3613-3619
[LCRP((PhP)2C2H4)][OTf] ( 4 a,b [OTf]) and [LCiPrP(PPh2)2][OTf] ( 5 b [OTf]) were prepared from the reaction of imidazoliumyl-substituted dipyrazolylphosphane triflate salts [LCRP(pyr)2][OTf] ( 3 a,b [OTf]; a : R=Me, b =iPr; LCR=1,3-dialkyl-4,5-dimethylimidazol-2-yl; pyr=3,5-dimethylpyrazol-1-yl) with the secondary phosphanes PhP(H)C2H4P(H)Ph) and Ph2PH. A stepwise double P−N/P−P bond metathesis to catena-tetraphosphane-2,3-diium triflate salt [(Ph2P)2(LCMeP)2][OTf]2 ( 7 a [OTf]2) is observed when reacting 3 a [OTf] with diphosphane P2Ph4. The coordination ability of 5 b [OTf] was probed with selected coinage metal salts [Cu(CH3CN)4]OTf, AgOTf and AuCl(tht) (tht=tetrahydrothiophene). For AuCl(tht), the helical complex [{(Ph2PPLCiPr)Au}4][OTf]4 ( 9 [OTf]4) was unexpectedly formed as a result of a chloride-induced P−P bond cleavage. The weakly coordinating triflate anion enables the formation of the expected copper(I) and silver(I) complexes [( 5 b )M(CH3CN)3][OTf]2 (M=Cu, Ag) ( 10 [OTf]2, 11 [OTf]2). 相似文献
14.
Dr. Céline Pichon Dr. Nicolas Suaud Valentin Jubault Dr. Carine Duhayon Prof. Nathalie Guihéry Dr. Jean-Pascal Sutter 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(62):15484-15495
Trinuclear systems of formula [{Cr(LN3O2Ph)(CN)2}2M(H2LN3O2R)] (M=MnII and FeII, LN3O2R stands for pentadentate ligands) were prepared in order to assess the influence of the bending of the apical M−N≡C linkages on the magnetic anisotropy of the FeII derivatives and in turn on their Single-Molecule Magnet (SMM) behaviors. The cyanido-bridged [Cr2M] derivatives were obtained by assembling trans-dicyanido CrIII complex [Cr(LN3O2Ph)(CN)2]− and divalent pentagonal bipyramid complexes [MII(H2LN3O2R)]2+ with various R substituents (R=NH2, cyclohexyl, S,S-mandelic) imparting different steric demand to the central moiety of the complexes. A comparative examination of the structural and magnetic properties showed an obvious effect of the deviation from straightness of the M−N≡C alignment on the slow relaxation of the magnetization exhibited by the [Cr2Fe] complexes. Theoretical calculations have highlighted important effects of the bending of the apical C−N−Fe linkages on both the magnetic anisotropy of the FeII center and the exchange interactions with the CrIII units. 相似文献
15.
Anxun Zheng Dr. Cheng-Bin Gong Dr. Cheuk-Fai Chow 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(63):14461-14466
The catalytic chemosensing assay (CCA), a new indicator displacement assay, was developed for selective detection of methomyl, a highly toxic pesticide. Trimetallic complex {[FeII(dmbpy)(CN)4]-[PtII(DMSO)Cl]2-[RuII(bpy)2(CN)2]} ( 1 ; dmbpy=4,4′-dimethyl-2,2′-bipyridine, bpy=2,2′-bipyridine) was synthesized as a task-specific catalyst to initially reduce and degrade methomyl to CH3SH/CH3NH2/CH3CN/CO2. The thus-produced CH3SH interacts with the trimetallic complex to displace the cis-[RuII(bpy)2(CN)2] luminophore for monitoring. Other pesticides, including organophosphates and similar carbamate pesticides, remained intact under the same catalytic conditions; a selective sensing signal is only activated when 1 recognizes methomyl. Furthermore, 1 can be applied to detect methomyl in real water samples. In the luminescent mode of the assay, the method detection limit (MDL) of 1 for methomyl (LD50=17 mg kg−1) was 1.12 mg L−1. 相似文献
16.
The Building Block [FeIII(pzphen)(CN)4]– and its Lanthanide Complexes: Synthesis,Crystal Structure,and Magnetic Properties 下载免费PDF全文
Jian‐Qing Tao Wen‐Wen Ju Zhou Zhou Li‐Yong Jia Ning‐Ning Chen Yun‐Shan Xue Jun Wang Xing‐Cai Huang 《无机化学与普通化学杂志》2016,642(24):1466-1471
The cyanide building block [FeIII(pzphen)(CN)4]– and its four lanthanide complexes [{FeIII(pzphen)(CN)4}2LnIII(H2O)5(DMF)3] · (NO3) · 2(H2O) · (CH3CN) [Ln = Nd ( 1 ), Sm ( 2 ), DMF = dimethyl formamide] and [{FeIII(pzphen)(CN)4}2LnIII(NO3)(H2O)2(DMF)2](CH3CN) [Ln = Gd ( 3 ), Dy ( 4 )] were synthesized and structurally characterized by single‐crystal X‐ray diffraction. Compounds 1 and 2 are ionic salts with two [FeIII(pzphen)(CN)4]– cations and one LnIII ion, but compounds 3 and 4 are cyano‐bridged FeIII‐LnIII heterometallic 3d‐4f complexes exhibiting a trinuclear structure in the same conditions. Magnetic studies show that compound 3 is antiferromagnetic between the central FeIII and GdIII atoms. Furthermore, the trinuclear cyano‐bridged FeIII2DyIII compound 4 displays no single‐molecular magnets (SMMs) behavior by the alternating current magnetic susceptibility measurements. 相似文献
17.
Alessia Barbieri Stefano Di Stefano Andrea Lapi Marco Mazzonna Giorgio Olivo 《Phosphorus, sulfur, and silicon and the related elements》2017,192(2):241-244
ABSTRACTThe oxidation of a series of aryl 1-methyl-1-phenylethyl sulfides with H2O2 catalyzed by the two tetradentate nonheme-iron complexes [(PDP)FeII(SbF6)2] and [(BPMCN)FeII(OTf)2] occurs by an electron transfer-oxygen transfer (ET/OT) mechanism as supported by the observation of products deriving from fragmentation of the corresponding radical cations in association with S-oxidation products (sulfoxides). 相似文献
18.
HaiLong Wang Kang Wang Wei Cao Ming Bai YongZhong Bian JianZhuang Jiang 《中国科学:化学(英文版)》2012,55(6):978-986
Four cyanide-bridged heterometallic complexes {[CuPb(L 1 )][Fe III (bpb)(CN) 2 ]} 2 ·(ClO 4 ) 2 ·2H 2 O·2CH 3 CN (1), {[CuPb(L 1 )] 2 [Fe II (CN) 6 ](H 2 O) 2 }·10H 2 O (2), {[Cu 2 (L 2 )][Fe III (bpb)(CN) 2 ] 2 }·2H 2 O·2CH 3 OH (3) and {[Cu 2 (L 2 )] 3 [Fe III (CN) 6 ] 2 (H 2 O) 2 }·10H 2 O (4) have been synthesized by treating K[Fe III (bpb)(CN) 2 ] [bpb 2-=1,2-bis(pyridine-2-carboxamido)benzenate] and K 3 [Fe III (CN)] 6 with dinuclear compartmental macrocyclic Schiff-base complexes [CuPb(L 1 )] (ClO 4 ) 2 or [Cu 2 (L 2 )]·(ClO 4 ) 2 , in which H 2 L 1 was derived from 2,6-diformyl-4-methyl-phenol, ethylenediamine, and diethylenetriamine in the molar ratio of 2:1:1 and H 2 L 2 from 2,6-diformyl-4-methyl-phenol and propylenediamine in the molar ratio of 1:1. Single crystal X-ray diffraction analysis reveals that compound 1 displays a cyclic hexanuclear heterotrimetallic molecular structure with alternating [FeⅢ (bpb)(CN) 2 ]- and [CuPb(L 1 )] 2+ units. Complex 2 is of a neutral dumb-bell-type pentanuclear molecular configuration consisting of one [Fe(CN)6] 4- anion sandwiched in two [CuPu(L 1 )] 2+ cations, and the pentanuclear moieties are further connected by the hydrogen bonding to give a 2D supramolecular framework. Heterobimetallic complex 3 is a tetranuclear molecule composed of a centrosymmetric [Cu 2 (L2)] 2+ segment and two terminal cyanide-containing blocks [FeⅢ (bpb)(CN)2 ]- . Octanuclear compound 4 is built from two [Fe(CN)6]3- anions sandwiched in the three [Cu 2 L 2 ] 2+ cations. Investigation of their magnetic properties reveals the overall antiferromagnetic behavior in the series of complexes except 2. 相似文献
19.
The mechanism for inhibition of [FeFe]-hydrogenases by formaldehyde is examined with model complexes. Key findings: (i) CH2 donated by formaldehyde covalently link Fe and the amine cofactor, blocking the active site and (ii) the resulting Fe-alkyl is a versatile electrophilic alkylating agent. Solutions of Fe2[(μ-SCH2)2NH](CO)4(PMe3)2 (1) react with a mixture of HBF4 and CH2O to give three isomers of [Fe2[(μ-SCH2)2NCH2](CO)4(PMe3)2]+ ([2]+). X-ray crystallography verified the NCH2Fe linkage to an octahedral Fe(ii) site. Although [2]+ is stereochemically rigid on the NMR timescale, spin-saturation transfer experiments implicate reversible dissociation of the Fe–CH2 bond, allowing interchange of all three diastereoisomers. Using 13CH2O, the methylenation begins with formation of [Fe2[(μ-SCH2)2N13CH2OH](CO)4(PMe3)2]+. Protonation converts this hydroxymethyl derivative to [2]+, concomitant with 13C-labelling of all three methylene groups. The Fe–CH2N bond in [2]+ is electrophilic: PPh3, hydroxide, and hydride give, respectively, the phosphonium [Fe2[(μ-SCH2)2NCH2PPh3](CO)4(PMe3)2]+, 1, and the methylamine Fe2[(μ-SCH2)2NCH3](CO)4(PMe3)2. The reaction of [Fe2[(μ-SCH2)2NH](CN)2(CO)4]2− with CH2O/HBF4 gave [Fe2[(μ-SCH2)2NCH2CN](CN)(CO)5]− ([4]−), the result of reductive elimination from [Fe2[(μ-SCH2)2NCH2](CN)2(CO)4]−. The phosphine derivative [Fe2[(μ-SCH2)2NCH2CN](CN)(CO)4(PPh3)]− ([5]−) was characterized crystallographically.The mechanism for inhibition of [FeFe]-hydrogenases by formaldehyde is examined with model complexes. 相似文献
20.
Wen Wen Yin‐Shan Meng Cheng‐Qi Jiao Qiang Liu Hai‐Lang Zhu Ya‐Ming Li Hiroki Oshio Tao Liu 《Angewandte Chemie (International ed. in English)》2020,59(38):16393-16397
It is promising and challenging to manipulate the electronic structures and functions of materials utilizing both metal‐to‐metal charge transfer (MMCT) and spin‐crossover (SCO) to tune the valence and spin states of metal ions. Herein, a metallocyanate building block is used to link with a FeII‐triazole moiety and generates a mixed‐valence complex {[(Tp4‐Me)FeIII(CN)3]9[FeII4(trz‐ph)6]}?[Ph3PMe]2?[(Tp4‐Me)FeIII(CN)3] ( 1 ; trz‐ph=4‐phenyl‐4H‐1,2,4‐triazole). Moreover, MMCT occurs between FeIII and one of the FeII sites after heat treatment, resulting in the generation of a new phase, {[(Tp4‐Me)FeII(CN)3][(Tp4‐Me)FeIII(CN)3]8 [FeIIIFeII3(trz‐ph)6]}? [Ph3PMe]2?[(Tp4‐Me)FeIII(CN)3] ( 1 a ). Structural and magnetic studies reveal that MMCT can tune the two‐step SCO behavior of 1 into one‐step SCO behavior of 1 a . Our work demonstrates that the integration of MMCT and SCO can provide a new alternative for manipulating functional spin‐transition materials with accessible multi‐electronic states. 相似文献