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1.
Cerium(IV) Hexanuclear Clusters from Cerium(III) Precursors: Molecular Models for Oxidative Growth of Ceria Nanoparticles
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Dr. Laurent Mathey Mitali Paul Prof. Dr. Christophe Copéret Prof. Dr. Hayato Tsurugi Prof. Dr. Kazushi Mashima 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(38):13454-13461
Reactions of cerium(III) nitrate, Ce(NO3)3?6 H2O, with different carboxylic acids, such as pivalic acid, benzoic acid, and 4‐methoxybenzoic acid, in the presence of a tridentate N,N,N‐donor ligand, diethylenetriamine (L1), under aerobic conditions yielded the corresponding cerium hexamers Ce6O8(O2CtBu)8(L1)4 ( 1 ), Ce6O8(O2CC6H5)8(L1)4 ( 2 ), and Ce6O8(O2CC6H4‐4‐OCH3)8(L1)4 ( 3 ). Hexamers 1 , 2 , and 3 contain the same octahedral CeIV6O8 core, in which all interstitial oxygen atoms are connected by μ3‐oxo bridging ligands. In contrast, treatment of the CeIV precursor (NH4)2Ce(NO3)6 (CAN) with pivalic acid and the ligand L1 under the same conditions afforded Ce6O4(OH)4(O2CtBu)12(L1)2 ( 4 ), exhibiting a deformed octahedral CeIV6O4(OH)4 core containing μ3‐oxo and μ3‐hydroxo moieties in defined positions. In contrast to the formation of 1 – 3 , the use of N‐methyldiethanolamine (L) in the reaction with Ce(NO3)3?6 H2O and pivalic acid afforded a previously reported CeIII dinuclear cluster, Ce2(O2CtBu)6L2, even in the presence of dioxygen. ESI‐MS analysis of the reaction mixture clearly indicated the importance of the ligand L1 in promoting oxidation of the CeIII aggregates, [Cen(O2CtBu)3n(L1)2], which is necessary for the formation of CeIV hexamers. 相似文献
2.
Polly L. Arnold Ian J. Casely Sergey Zlatogorsky Claire Wilson 《Helvetica chimica acta》2009,92(11):2291-2303
The use of tetravalent cerium alkoxides, nitrates, and triflates was studied as a direct route to [CeIV(carbene)] complexes. Protonolysis reactions between 1H‐imidazolium‐ or imidazoline (=4,5‐dihydro‐1H‐imidazole)‐containing alkoxide proligands HL (L=OCMe2CH2[1‐C(NCHCHNiPr)]) and HLS (LS=OCMe2CH2[1‐C(NCH2CH2NiPr)]) and CeIV tert‐butoxide, triflate, and nitrate compounds were studied to target [CeIV(N‐heterocyclic carbene)] complexes (of unsaturated and saturated carbenes, resp.). Instead, tetravalent cerium imidazolium [(OtBu)3Ce(μ‐OtBu)2(μ‐HL)Ce(OtBu)3], or imidazolinium adducts [(OtBu)3Ce(μ‐OtBu)2(μ‐HLS)Ce(OtBu)3] were isolated. However, the salt metathesis of cerium triflate with KL provided a simple route to [CeL4], which was significantly improved if an external oxidant, benzoquinone, was included in the mixture to maintain oxidation‐state integrity. Likewise, the salt metathesis of cerium triiodide with KL and added benzoquinone provided a straightforward route to [CeL4]. 相似文献
3.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(31):9219-9223
Ceric ammonium nitrate (CAN) or CeIV(NH4)2(NO3)6 is often used in artificial water oxidation and generally considered to be an outer‐sphere oxidant. Herein we report the spectroscopic and crystallographic characterization of [(N4Py)FeIII‐O‐CeIV(OH2)(NO3)4]+ ( 3 ), a complex obtained from the reaction of [(N4Py)FeII(NCMe)]2+ with 2 equiv CAN or [(N4Py)FeIV=O]2+ ( 2 ) with CeIII(NO3)3 in MeCN. Surprisingly, the formation of 3 is reversible, the position of the equilibrium being dependent on the MeCN/water ratio of the solvent. These results suggest that the FeIV and CeIV centers have comparable reduction potentials. Moreover, the equilibrium entails a change in iron spin state, from S =1 FeIV in 2 to S =5/2 in 3 , which is found to be facile despite the formal spin‐forbidden nature of this process. This observation suggests that FeIV=O complexes may avail of reaction pathways involving multiple spin states having little or no barrier. 相似文献
4.
Ying‐Hong Lu Hoong‐Kun Fun Suchada Chantrapromma Ibrahim Abdul Razak Zhen Shen Jing‐Lin Zuo Xiao‐Zeng You 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(8):911-913
The title dinuclear di‐μ‐oxo‐bis[(1,4,8,11‐tetraazacyclotetradecane‐κ4N)manganese(III,IV)] diperchlorate nitrate complex, [Mn2O2(C10H24N4)2](ClO4)2(NO3) or [(cyclam)MnO]2(ClO4)2(NO3), was self‐assembled by the reaction of Mn2+ with 1,4,8,11‐tetraazacyclotetradecane in aqueous media. The structure of this compound consists of a centrosymmetric binuclear [(cyclam)MnO]3+ unit, two perchlorate anions and one nitrate anion. While the low‐temperature electron paramagnetic resonance spectra show a typical 16‐line signal for a di‐μ‐oxo MnIII/MnIV dimer, the magnetic susceptibility studies also confirm a characteristic antiferromagnetic coupling between the electronic spins of the MnIV and MnIII ions. 相似文献
5.
Cerium‐Complex‐Catalyzed Oxidation of Arylmethanols under Atmospheric Pressure of Dioxygen and Its Mechanism through a Side‐On μ‐Peroxo Dicerium(IV) Complex
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Mitali Paul Satoru Shirase Dr. Yuma Morimoto Dr. Laurent Mathey Dr. Balasubramanian Murugesapandian Dr. Shinji Tanaka Prof. Dr. Shinobu Itoh Prof. Dr. Hayato Tsurugi Prof. Dr. Kazushi Mashima 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(12):4008-4014
A new CeIV complex [Ce{NH(CH2CH2N=CHC6H2‐3,5‐(tBu)2‐2‐O)2}(NO3)2] ( 1 ), bearing a dianionic pentadentate ligand with an N3O2 donor set, has been prepared by treating (NH4)2Ce(NO3)6 with the sodium salt of ligand L1 . Complex 1 in the presence of TEMPO and 4 Å molecular sieves (MS4 A) has been found to serve as a catalyst for the oxidation of arylmethanols using dioxygen as an oxidant. We propose an oxidation mechanism based on the isolation and reactivity study of a trivalent cerium complex [Ce{NH(CH2CH2N=CHC6H2‐3,5‐(tBu)2‐2‐O)2}(NO3)(THF)] ( 2 ), its side‐on μ‐O2 adduct [Ce{NH(CH2CH2N=CHC6H2‐3,5‐(tBu)2‐2‐O)2}(NO3)]2(μ‐η2:η2‐O2) ( 3 ), and the hydroxo‐bridged CeIV complex [Ce{NH(CH2CH2N=CHC6H2‐3,5‐(tBu)2‐2‐O)2}(NO3)]2(μ‐OH)2 ( 4 ) as key intermediates during the catalytic cycle. Complex 2 was synthesized by reduction of 1 with 2,5‐dimethyl‐1,4‐bis(trimethylsilyl)‐1,4‐diazacyclohexadiene. Bubbling O2 into a solution of 2 resulted in formation of the peroxo complex 3 . This provides the first direct evidence for cerium‐catalyzed oxidation of alcohols under an O2 atmosphere. 相似文献
6.
Mechanistic Insight into the Nitric Oxide Dioxygenation Reaction of Nonheme Iron(III)–Superoxo and Manganese(IV)–Peroxo Complexes
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Dr. Seungwoo Hong Dr. Pankaj Kumar Dr. Kyung‐Bin Cho Dr. Yong‐Min Lee Prof. Dr. Kenneth D. Karlin Prof. Dr. Wonwoo Nam 《Angewandte Chemie (International ed. in English)》2016,55(40):12403-12407
Reactions of nonheme FeIII–superoxo and MnIV–peroxo complexes bearing a common tetraamido macrocyclic ligand (TAML), namely [(TAML)FeIII(O2)]2? and [(TAML)MnIV(O2)]2?, with nitric oxide (NO) afford the FeIII–NO3 complex [(TAML)FeIII(NO3)]2? and the MnV–oxo complex [(TAML)MnV(O)]? plus NO2?, respectively. Mechanistic studies, including density functional theory (DFT) calculations, reveal that MIII–peroxynitrite (M=Fe and Mn) species, generated in the reactions of [(TAML)FeIII(O2)]2? and [(TAML)MnIV(O2)]2? with NO, are converted into MIV(O) and .NO2 species through O?O bond homolysis of the peroxynitrite ligand. Then, a rebound of FeIV(O) with .NO2 affords [(TAML)FeIII(NO3)]2?, whereas electron transfer from MnIV(O) to .NO2 yields [(TAML)MnV(O)]? plus NO2?. 相似文献
7.
Clément Camp Victor Mougel Dr. Jacques Pécaut Prof. Laurent Maron Dr. Marinella Mazzanti 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(51):17528-17540
Two new arene inverted‐sandwich complexes of uranium supported by siloxide ancillary ligands [K{U(OSi(OtBu)3)3}2(μ‐η6:η6‐C7H8)] ( 3 ) and [K2{U(OSi(OtBu)3)3}2(μ‐η6:η6‐C7H8)] ( 4 ) were synthesized by the reduction of the parent arene‐bridged complex [{U(OSi(OtBu)3)3}2(μ‐η6:η6‐C7H8)] ( 2 ) with stoichiometric amounts of KC8 yielding a rare family of inverted‐sandwich complexes in three states of charge. The structural data and computational studies of the electronic structure are in agreement with the presence of high‐valent uranium centers bridged by a reduced tetra‐anionic toluene with the best formulation being UV–(arene4?)–UV, KUIV–(arene4?)–UV, and K2UIV–(arene4?)–UIV for complexes 2 , 3 , and 4 respectively. The potassium cations in complexes 3 and 4 are coordinated to the siloxide ligands both in the solid state and in solution. The addition of KOTf (OTf=triflate) to the neutral compound 2 promotes its disproportionation to yield complexes 3 and 4 (depending on the stoichiometry) and the UIV mononuclear complex [U(OSi(OtBu)3)3(OTf)(thf)2] ( 5 ). This unprecedented reactivity demonstrates the key role of potassium for the stability of these complexes. 相似文献
8.
Uwe Bayer Daniel Werner Ccilia Maichle‐Mssmer Reiner Anwander 《Angewandte Chemie (International ed. in English)》2020,59(14):5830-5836
The homoleptic pyrazolate complexes [CeIII4(Me2pz)12] and [CeIV(Me2pz)4]2 quantitatively insert CO2 to give [CeIII4(Me2pz?CO2)12] and [CeIV(Me2pz?CO2)4], respectively (Me2pz=3,5‐dimethylpyrazolato). This process is reversible for both complexes, as observed by in situ IR and NMR spectroscopy in solution and by TGA in the solid state. By adjusting the molar ratio, one molecule of CO2 per [CeIV(Me2pz)4] complex could be inserted to give trimetallic [Ce3(Me2pz)9(Me2pz?CO2)3(thf)]. Both the cerous and ceric insertion products catalyze the formation of cyclic carbonates from epoxides and CO2 under mild conditions. In the absence of epoxide, the ceric catalyst is prone to reduction by the co‐catalyst tetra‐n‐butylammonium bromide (TBAB). 相似文献
9.
Dr. Apparao Draksharapu Waqas Rasheed Dr. Johannes E. M. N. Klein Prof. Dr. Lawrence Que Jr. 《Angewandte Chemie (International ed. in English)》2017,56(31):9091-9095
Ceric ammonium nitrate (CAN) or CeIV(NH4)2(NO3)6 is often used in artificial water oxidation and generally considered to be an outer-sphere oxidant. Herein we report the spectroscopic and crystallographic characterization of [(N4Py)FeIII-O-CeIV(OH2)(NO3)4]+ ( 3 ), a complex obtained from the reaction of [(N4Py)FeII(NCMe)]2+ with 2 equiv CAN or [(N4Py)FeIV=O]2+ ( 2 ) with CeIII(NO3)3 in MeCN. Surprisingly, the formation of 3 is reversible, the position of the equilibrium being dependent on the MeCN/water ratio of the solvent. These results suggest that the FeIV and CeIV centers have comparable reduction potentials. Moreover, the equilibrium entails a change in iron spin state, from S=1 FeIV in 2 to S=5/2 in 3 , which is found to be facile despite the formal spin-forbidden nature of this process. This observation suggests that FeIV=O complexes may avail of reaction pathways involving multiple spin states having little or no barrier. 相似文献
10.
Deepika G. Karmalkar Muniyandi Sankaralingam Mi Sook Seo Roman Ezhov Yong‐Min Lee Yulia N. Pushkar Won‐Suk Kim Shunichi Fukuzumi Wonwoo Nam 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(45):16270-16275
A mononuclear nonheme manganese(IV)–oxo complex binding the Ce4+ ion, [(dpaq)MnIV(O)]+–Ce4+ ( 1 ‐Ce4+), was synthesized by reacting [(dpaq)MnIII(OH)]+ ( 2 ) with cerium ammonium nitrate (CAN). 1 ‐Ce4+ was characterized using various spectroscopic techniques, such as UV/Vis, EPR, CSI‐MS, resonance Raman, XANES, and EXAFS, showing an Mn?O bond distance of 1.69 Å with a resonance Raman band at 675 cm?1. Electron‐transfer and oxygen atom transfer reactivities of 1 ‐Ce4+ were found to be greater than those of MnIV(O) intermediates binding redox‐inactive metal ions ( 1 ‐Mn+). This study reports the first example of a redox‐active Ce4+ ion‐bound MnIV‐oxo complex and its spectroscopic characterization and chemical properties. 相似文献
11.
In this paper, we present a mixed valence f–d Ce6Mn 4 III compound having formula [Ce 6 IV Mn 4 III (μ4-O)4 (μ3-O)4(O2CtBu)12(ea)4(OAc)4]·H2O (1), which is obtained by the reaction of hydrated lanthanide nitrate, pivalic acid, and ethanolamine in MeCN as a solvent. The single crystal X-ray diffraction analysis demonstrates that the central core consists of an octahedron with four triangular pyramids added to four related faces or as an octahedron encapsulated in a tetragon. The fitting of magnetization data using the anisotropic model gives D = 2.13 cm–1 and g = 1.97 (D is the axial zero-field splitting parameter). 相似文献
12.
Synthesis,Structure, and Reactivity of a Tetranuclear Cerium(IV) Oxo Cluster Supported by the Kläui Tripodal Ligand [Co(η5‐C5H5){P(O)(OEt)2}3]−
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Dr. Guo‐Cang Wang Dr. Yat‐Ming So Kang‐Long Wong Ka‐Chun Au‐Yeung Dr. Herman H.‐Y. Sung Prof. Ian D. Williams Prof. Wa‐Hung Leung 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(45):16126-16135
A tetranuclear CeIV oxo cluster compound containing the Kläui tripodal ligand [Co(η5‐C5H5){P(O)(OEt)2}3]? (LOEt?) has been synthesized and its reactions with H2O2, CO2, NO, and Brønsted acids have been studied. The treatment of [Ce(LOEt)(NO3)3] with Et4NOH in acetonitrile afforded the tetranuclear CeIV oxo cluster [Ce4(LOEt)4O7H2] ( 1 ) containing an adamantane‐like {Ce4(μ2‐O)6} core with a μ4‐oxo ligand at the center. The reaction of 1 with H2O2 resulted in the formation of the peroxo cluster [Ce4(LOEt)4(μ4‐O)(μ2‐O2)4(μ2‐OH)2] ( 2 ). The treatment of 1 with CO2 and NO led to isolation of [Ce(LOEt)2(CO3)] and [Ce(LOEt)(NO3)3], respectively. The protonation of 1 with HCl, ROH (R=2,4,6‐trichlorophenyl), and Ph3SiOH yielded [Ce(LOEt)Cl3] ( 3 ), [Ce(LOEt)(OR)3] ( 4 ), and [Ce(LOEt)(OSiPh3)3] ( 5 ), respectively. The chloride ligands in 3 are labile and can be abstracted by silver(I) salts. The treatment of 3 with AgOTs (OTs?=tosylate) and Ag2O afforded [Ce(LOEt)(OTs)3] ( 6 ) and 1 , respectively. The electrochemistry of the Ce‐LOEt complexes has been studied by using cyclic voltammetry. The crystal structures of complexes 1 – 5 have been determined. 相似文献
13.
Yating Chen Shaonan Zhang Yu Xiao Shuhua Zhang 《Acta Crystallographica. Section C, Structural Chemistry》2020,76(3):236-243
Three novel complexes, namely, penta‐μ‐acetato‐bis(μ2‐2‐{[2‐(6‐chloropyridin‐2‐yl)hydrazinylidene]methyl}‐6‐methoxyphenolato)‐μ‐formato‐tetramanganese(II), [Mn4(C13H11ClN3O2)2(C2H3O2)5.168(CHO2)0.832], 1 , hexa‐μ2‐acetato‐bis(μ2‐2‐{[2‐(6‐bromopyridin‐2‐yl)hydrazinylidene]methyl}‐6‐methoxyphenolato)tetramanganese(II), [Mn4(C13H11BrN3O2)2(C2H3O2)6], 2 , and catena‐poly[[μ2‐acetato‐acetatoaqua(μ2‐2‐{[2‐(6‐chloropyridin‐2‐yl)hydrazinylidene]methyl}‐6‐methoxyphenolato)dimanganese(II)]‐μ2‐acetato], [Mn2(C13H11ClN3O2)(C2H3O2)3(H2O)]n, 3 , have been synthesized using solvothermal methods. Complexes 1 – 3 were characterized by IR spectroscopy, elemental analysis and single‐crystal X‐ray diffraction. Complexes 1 and 2 are tetranuclear manganese clusters, while complex 3 has a one‐dimensional network based on tetranuclear Mn4(L1)2(CH3COO)6(H2O)2 building units (L1 is 2‐{[2‐(6‐chloropyridin‐2‐yl)hydrazinylidene]methyl}‐6‐methoxyphenolate). Magnetic studies reveal that complexes 1 – 3 display dominant antiferromagnetic interactions between MnII ions through μ2‐O bridges. In addition, 1 – 3 also display favourable electrochemiluminescence (ECL) properties. 相似文献
14.
A Novel Self‐assembled Nickel(II)‐Cerium(III) Heterotetranuclear Dimer Constructed from N2O2‐type Bisoxime and Terephthalic Acid: Synthesis,Structure, and Photophysical Properties
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By self‐assembly of a Salamo‐type ligand H2L [H2L = 1,2‐bis(3‐methoxysalicylideneaminooxy)ethane] with Ni(OAc)2 · 4H2O, Ce(NO3)3 · 6H2O, and H2bdc (H2bdc = terephthalic acid), a novel NiII‐CeIII heterometallic complex, [{Ni(L)Ce(NO3)2(CH3OH)(DMF)}2(bdc)], was obtained. Two crystallographically equivalent [Ni(L)Ce(NO3)2(CH3OH)(DMF)] moieties lie in the inversion center, and are linked by one bdc2– ligand leading to a heterotetranuclear dimer, in which the carboxylato group bridges the NiII and CeIII atoms. Moreover, the photophysical properties of the NiII‐CeIII complex were studied. 相似文献
15.
Alexander J. Blake Naomi A. Harris Deborah L. Kays William Lewis Graeme J. Moxey 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(8):m204-m206
The solid‐state structure of the title compound, [Na2Mn2(C32H56N2OSi2)2O2] or [1,8‐C10H6(NSiiPr3)2Mn(μ3‐O)Na(THF)]2, which lies across a crystallographic twofold axis, exhibits a central [Mn2O2Na2]4+ core, with two oxide groups, each triply bridging between the two MnIII ions and an Na+ ion. Additional coordination is provided to each MnIII centre by a 1,8‐C10H6(NSiiPr3)2 [1,8‐bis(triisopropylsilylamido)naphthalene] ligand and to the Na+ centres by a tetrahydrofuran molecule. The presence of an additional Na...H—C agostic interaction potentially contributes to the distortion around the bridging oxide group. 相似文献
16.
Eser S. Akturk Dr. Glenn P. A. Yap Prof. Dr. Klaus H. Theopold 《Angewandte Chemie (International ed. in English)》2015,54(49):14974-14977
A chromium(I) dinitrogen complex reacts rapidly with O2 to form the mononuclear dioxo complex [TptBu,MeCrV(O)2] (TptBu,Me=hydrotris(3‐tert‐butyl‐5‐methylpyrazolyl)borate), whereas the analogous reaction with sulfur stops at the persulfido complex [TptBu,MeCrIII(S2)]. The transformation of the putative peroxo intermediate [TptBu,MeCrIII(O2)] (S=3/2) into [TptBu,MeCrV(O)2] (S=1/2) is spin‐forbidden. The minimum‐energy crossing point for the two potential energy surfaces has been identified. Although the dinuclear complex [(TptBu,MeCr)2(μ‐O)2] exists, mechanistic experiments suggest that O2 activation occurs on a single metal center, by an oxidative addition on the quartet surface followed by crossover to the doublet surface. 相似文献
17.
Nayak S Evangelisti M Powell AK Reedijk J 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(43):12865-12872
Three high‐nuclearity mixed valence manganeseII/III coordination clusters, have been synthesised, that is, [Mn III 6Mn II 4(μ3‐O)4(HL1)6(μ3‐N3)3(μ3‐Br)(Br)](N3)0.7/(Br)0.3 ? 3 MeCN ? 2 MeOH ( 1 ) (H3L1=3‐methylpentan‐1,3,5‐triol), [MnIII11MnII6(μ4‐O)8(μ3‐Cl)4(μ,μ3‐O2CMe)2(μ,μ‐L2)10Cl2.34(O2CMe)0.66(py)3(MeCN)2] ? 7 MeCN ( 2 ) (H2L2=2,2‐dimethyl‐1,3‐propanediol and py is pyridine), and [MnIII12MnII7(μ4‐O)8(μ3‐η1N3)8(HL3)12(MeCN)6]Cl2 ? 10 MeOH ? MeCN ( 3 ) (H3L3=2,6‐bis(hydroxymethyl)‐4‐methylphenol) with high ground‐spin states, S=22, 28±1, and 83/2, respectively; their magnetothermal properties have been studied. The three compounds are based on a common supertetrahedral building block as seen in the Mn10 cluster. This fundamental magnetic unit is made up of a tetrahedron of MnII ions with six MnIII ions placed midway along each edge giving an inscribed octahedron. Thus, the fundamental building unit as represented by compound 1 can be described as a Mn10 supertetrahedron. Compounds 2 and 3 correspond to two such units joined by a common edge or vertex, respectively, resulting in Mn17 and Mn19 coordination clusters. Magnetothermal studies reveal that all three compounds show interesting long‐range magnetic ordering at low temperature, originating from negligible magnetic anisotropy of the compounds; compound 2 shows the largest magnetocaloric effect among the three compounds. This is as expected and can be attributed to the presence of a small magnetic anisotropy, and low‐lying excited states in compound 2 . 相似文献
18.
Variation of the reaction conditions with AgC??CR (R?=?Ph, t Bu), t BuPO3H2, (Et4N)VO3 and AgNO3 as starting materials afforded three isostructural globular neutral silver(I)-ethynide clusters incorporating the [( t BuPO3)4V4O8]4? unit as an integral shell component, namely {(NO3)2@Ag16(C??CPh)4[( t BuPO3)4V4O8]2(DEF)6(NO3)2}, {(NO3)2@Ag16(C??C t Bu)4[( t BuPO3)4V4O8]2(DMF)6(NO3)2}·DMF·2H2O and {(NO3)2@Ag16(C??C t Bu)4[( t BuPO3)4V4O8]2(DMF)6(NO3)2}·{(NO3)2@Ag16(C??C t Bu)4[( t BuPO3)4V4O8]2(DMF)4(py)2(NO3)2}·DMF·5H2O, in which the central cavity of each Ag16 cluster is occupied by two nitrate ions that function as a template. Furthermore, from the reaction of AgC??C t Bu with (NH4)4[V2O4(d,l-citrate)2]·4H2O, we isolated a new high-nuclearity silver(I)-ethynide cluster [(VO4)2@Ag34(C??C t Bu)22(NO3)6]·8H2O that encapsulates a pair of templating orthovanadate ions. 相似文献
19.
Sandip Mukherjee Prof. Dr. Partha Sarathi Mukherjee 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(50):17064-17074
Four new oxo‐centered MnIII‐salicylaldoximate triangle‐based extended complexes [MnIII6O2(salox)6(EtOH)4(phda)]n?(saloxH2)n?(2H2O)n ( 1 ), [MnIII6O2(salox)6(MeOH)5(5‐I‐isoph)]n?(3 MeOH)n ( 2 ), [MnIII6O2(salox)6(MeOH)4(H2O) (5‐N3‐isoph)]n?(4 MeOH)n ( 3 ) and [MnIII3NaO(salox)3(MeOH)4(5‐NO2‐isoph)]n?(MeOH)n (H2O)n ( 4 ) [salox=salicylaldoximate, phda=1,3‐phenylenediacetate, isoph=isophthalate] have been synthesized under similar reaction conditions. Single crystal X‐ray structures show that in 1 , only one type of Mn6 cluster is arranged in 1 D, whereas in 2 and 3 there are two types of clusters, differing in the way the triangle units are joined and assembled. In complex 4 , however, the basic building structure is heteronuclear and based on Mn3 units extended in 2 D. Susceptibility measurements (dc and ac) over a wide range of temperatures and fields show that the complexes 1 , 2 , and 3 behave as single molecule magnets (SMMs) with S=4 ground state, while 4 is dominantly antiferromagnetic with a ground spin state S=2. Density functional theory calculations have been performed on model complexes to provide a qualitative theoretical interpretation for their overall magnetic behavior. 相似文献
20.
Two tetranuclear manganese complexes, [NaMnIIMn3III(μ4‐O2–)(HL)3(SCN)4] ( 1 ) and [NaMnIIMn3III(μ4‐O2–)(HL)3Cl4][NaMnIIMn3III(μ4‐O2–)(HL)3Cl3(H2O)]ClO4 · 3.5H2O ( 2 ) were obtained from the reaction of manganese perchlorate with a quadridentate Schiff base ligand, 3‐(2‐hydroxybenzylideneamino)propane‐1, 2‐diol (H3L) derived from condensation of 2‐hydroxybenzaldehyde with 3‐amino‐1, 2‐propanediol, as well as the coligand KSCN or NaCl under basic conditions. Single‐crystal X‐ray studies reveal that those two complexes all have a mixed‐valent tetrahedral core, which contains an apical MnII ion and three basal MnIII ions situated in the [Mn3(μ4‐O2–)]7+ equilateral triangle plane. Fitting of the magnetic susceptibility data to the theoretical χmT vs. T expression, revealed that the presence of only antiferromagnetic interactions between the central metal atoms in 1 , while both antiferromagnetic and ferromagnetic interactions are present in 2 . 相似文献