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1.
Simon Smolders Tom Willhammar Andra Krajnc Kadir Sentosun Michael T. Wharmby Kirill A. Lomachenko Sara Bals Gregor Mali Maarten B. J. Roeffaers Dirk E. DeVos Bart Bueken 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(27):9258-9263
While titanium‐based metal–organic frameworks (MOFs) have been widely studied for their (photo)catalytic potential, only a few TiIV MOFs have been reported owing to the high reactivity of the employed titanium precursors. The synthesis of COK‐47 is now presented, the first Ti carboxylate MOF based on sheets of TiIVO6 octahedra, which can be synthesized with a range of different linkers. COK‐47 can be synthesized as an inherently defective nanoparticulate material, rendering it a highly efficient catalyst for the oxidation of thiophenes. Its structure was determined by continuous rotation electron diffraction and studied in depth by X‐ray total scattering, EXAFS, and solid‐state NMR. Furthermore, its photoactivity was investigated by electron paramagnetic resonance and demonstrated by catalytic photodegradation of rhodamine 6G. 相似文献
2.
Jie Chen Ning‐Hai Hu Jie Zhan Yue‐Sheng Li 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(7):m337-m338
A new polynuclear titanium(IV) complex, dichlorodeca‐μ2‐oxo‐hexakis(pentamethylcyclopentadienyl)hexatitanium(IV), [Ti6(C10H15)6Cl2O10], has been synthesized by hydrolysis of a titanium complex bearing an N‐(2‐hydroxy‐3,5‐dimethylbenzyl)diethanolamine Mannich ligand. The molecule has two O‐bridged Ti3O3 rings linked to two similar rings through a tetrahedrally O‐coordinated Ti atom. All Ti atoms except the central one are coordinated to pentamethylcyclopentadienyl (Cp*) ligands. The Cp* ligands are arranged with approximate symmetry with respect to the Ti/O/Cl core. 相似文献
3.
Li Song Chun Ling Xinping Wang 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(12):m384-m386
The title racemic heterometallic dinuclear compound, [MnSn(C2H2O2S)3(H2O)5], (I), contains one main group SnIV metal centre and one transition metal MnII centre, and, by design, links the MnII centre to the building unit of the (Δ/Λ) [SnL3]2− complex anion (L is the 2‐sulfidoacetate dianion). In this cluster, the SnIV centre of the (Δ/Λ) [SnL3]2− unit is coordinated by three O atoms and three S atoms from three L ligands to form an [SnO3S3] octahedral coordination environment. The MnII centre is in an [MnO6] octahedral coordination environment, with five O atoms from five water molecules and the sixth from the μ2‐L ligand of the (Δ/Λ) [SnL3]2− unit. Between adjacent dinuclear molecules, there are many hydrogen‐bond interactions of O—H...O, O—H...S, C—H...O and C—H...S types. Of these, eight pairs of O—H...O hydrogen bonds fuse all the dinuclear molecules into two‐dimensional supramolecular sheets along the bc plane. Adjacent supramolecular sheets are further connected through O—H...S hydrogen bonds to give a three‐dimensional supramolecular network. 相似文献
4.
A polymeric VIV‐Cd compound, {(NH4)2[(VIVO)2(μ2‐O)(nta)2Cd(H2O)2]·H2O}n (H3nta = nitrilotriacetic acid), has been prepared and characterized by single‐crystal X‐ray diffraction. The compound crystallizes in the monoclinic space group C2/c with a = 17.3760(2) Å, b = 8.0488(1) Å, c = 17.3380(2) Å, β = 107.9690(10)°, V = 2306.55(5) Å3, Z = 4, and R1 = 0.0303 for 1958 observed reflections. The structure exhibits a heterometallic three‐dimensional network formed by polymeric [(VIVO)2(μ2‐O)(nta)2Cd(H2O)2]2? anions. 相似文献
5.
A Square‐Planar Tetracoordinate Oxygen‐Containing Ti4O17 Cluster Stabilized by Two 1,1′‐Ferrocenedicarboxylato Ligands 下载免费PDF全文
Dr. Zhichang Liu Juying Lei Dr. Marco Frasconi Dr. Xiaohu Li Dennis Cao Dr. Zhixue Zhu Dr. Severin T. Schneebeli Prof. George C. Schatz Prof. J. Fraser Stoddart 《Angewandte Chemie (International ed. in English)》2014,53(35):9193-9197
By introducing steric constraints into molecular compounds, it is possible to achieve atypical coordination geometries for the elements. Herein, we demonstrate that a titanium‐oxo cluster [{Ti4(μ4‐O)(μ2‐O)2}(OPri)6(fdc)2], which possesses a unique edge‐sharing Ti4O17 octahedron tetramer core, is stabilized by the constraints produced by two orthogonal 1,1′‐ferrocenedicarboxylato (fdc) ligands. As a result, a square‐planar tetracoordinate oxygen (ptO) can be generated. The bonding pattern of this unusual anti‐van’t Hoff/Le Bel oxygen, which has been probed by theoretical calculations, can be described by two horizontally σ‐bonded 2px and 2py orbitals along with one perpendicular nonbonded 2pz orbital. While the two ferrocene units are separated spatially by the ptO with an Fe???Fe separation of 10.4 Å, electronic communication between them still takes place as revealed by the cluster’s two distinct one‐electron electrochemical oxidation processes. 相似文献
6.
Kinetic studies on the oxidation of 2‐mercaptosuccinic acid by dinuclear [Mn2III/IV(μ‐O)2(cyclam)2](ClO4)3] ( 1 ) (abbreviated as MnIII–MnIV) (cyclam = 1,4,8,11‐tetraaza‐cyclotetradecane) have been carried out in aqueous medium in the pH range of 4.0–6.0, in the presence of acetate buffer at 30°C by UV–vis spectrophotometry. In the pH region, two species of complex 1 (MnIII–MnIV and MnIII–MnIVH, the later being μ‐O protonated form) were found to be kinetically significant. The first‐order dependence of the rate of the reactions on [Thiol] both in presence and absence of externally added copper(II) ions, first‐order dependence on [Cu2+] and a decrease of rate of the reactions with increase in pH have been rationalized by suitable sequence of reactions. Protonation of μ‐O bridge of 1 is evidenced by the perchloric acid catalyzed decomposition of 1 to mononuclear Mn(III) and Mn(IV) complex observed by UV–vis and EPR spectroscopy. The kinetic features have been rationalized considering Cu(RSH) as the reactive intermediate. EPR spectroscopy lends support for this. The formation of a hydrogen bonded outer‐sphere adduct between the reductant and the complex in the lower pH range prior to electron transfer reactions is most likely to occur. © 2004 Wiley Periodicals, Inc. Int J Chem Kinet 36: 170–177 2004 相似文献
7.
Ana María Atria Maria Teresa Garland Ricardo Baggio 《Acta Crystallographica. Section C, Structural Chemistry》2012,68(7):m185-m188
The title ionic compound, (C7H8N3)2[Ho2(C4H5O2)8], is constructed from two almost identical independent centrosymmetric anionic dimers balanced by two independent 2‐amino‐1H‐benzimidazol‐3‐ium (Habim+) cations. The asymmetric part of each dimer is made up of one HoIII cation and four crotonate (crot or but‐2‐enoate) anions, two of them acting in a simple η2‐chelating mode and the remaining two acting in two different μ2:η2 fashions, viz. purely bridging and bridging–chelating. Symmetry‐related HoIII cations are linked by two Ho—O—Ho and two Ho—O—C—O—Ho bridges which lead to rather short intracationic Ho...Ho distances [3.8418 (3) and 3.8246 (3) Å]. In addition to the obvious Coulombic interactions linking the cations and anions, the isolated [Ho2(crot)8]2− and Habim+ ions are linked by a number of N—H...O hydrogen bonds, in which all N—H groups of the cation are involved as donors and all (simple chelating) crot O atoms are involved as acceptors. These interactions result in compact two‐dimensional structures parallel to (110), which are linked to each other by weaker π–π contacts between Habim+ benzene groups. 相似文献
8.
Jeanet Conradie 《International journal of quantum chemistry》2010,110(5):1100-1107
Density functional theory calculations show that the formal 16‐electron count of d0 [Cp2TiIV(O,O′‐BID)]0/1 complexes containing a O,O′‐chelated bidentate ligand O,O′‐BID of different ring size, is increased via Ti←O π bonding when both the O donor atoms carry a formal negative charge. The Ti←O π bonding occurs by symmetry lowering of the complex by either symmetrical (Cs) or unsymmetrical (C2) folding of the O,O′‐BID ligand round the O···O axis. An NBO analysis confirms the Ti←O π charge transfer via back‐bonding. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010 相似文献
9.
Tegan Thomas David Pugh Ivan P. Parkin Claire J. Carmalt 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(7):m234-m236
The title compound, [Ti2Cl6(C2H6N)2(C2H7N)2], is a binuclear octahedral complex lying about an inversion centre. There are four different chloride environments, two terminal [Ti—Cl = 2.2847 (5) and 2.3371 (5) Å] and two bridging [Ti—Cl = 2.4414 (5) and 2.6759 (5) Å], with the Ti—Cl distances being strongly influenced by both the ligand trans to the chloride and whether or not the chloride anion is bridging between the two TiIV centres. The compound forms a two‐dimensional network in the solid state, with weak intermolecular C—H...Cl interactions giving rise to a planar network in the (10) plane. 相似文献
10.
A comparative kinetic study of the reactions of two mixed valence manganese(III,IV) complexes of macrocyclic ligands, [L1MnIV(O)2MnIIIL1], 1 (L1 = 1,4,8,11‐tetraazacyclotetradecane) and [L2MnIV(O)2MnIIIL2], 2 (L2 = 1,4,7,10‐tetraazacyclododecane) with thiosulfate has been carried out by spectrophotometry in aqueous buffer at 30°C. Reaction between complex 1 and thiosulfate follows a first‐order rate saturation kinetics. The pH dependency and kinetic evidences suggest the participation of two complex species of MnIII(μ‐O)2MnIV under the experimental conditions. Detailed kinetic study shows that reduction of 2 proceeds through an autocatalytic path where the intermediate (MnIII)2 species has been assumed to catalyze the reaction. The difference in the reaction mechanisms is ascribed to the difference in stability of the intermediate complex species, the evidence for which comes from the electrochemical behavior of the complexes and time dependent EPR spectroscopic measurements during the reduction of 2 . © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 36: 119–128, 2004 相似文献
11.
The first selenite chloride hydrates, Co(HSeO3)Cl · 3 H2O and Cu(HSeO3)Cl · 2 H2O, have been prepared from solution and characterised by single‐crystal X‐ray diffraction. The cobalt phase adopts an unusual “one‐dimensional” structure built up from vertex‐sharing pyramidal [HSeO3]2–, and octahedral [CoO2(H2O)4]2– and [CoO2(H2O)2Cl2]4– units. Inter‐chain bonding is by way of hydrogen bonds or van der Waals' interactions. The atomic arrangement of the copper phase involves [HSeO3]2– pyramids and Jahn‐Teller distorted [CuCl2(H2O)4] and [CuO4Cl2]8– octahedra, sharing vertices by way of Cu–O–Se and Cu–Cl–Cu bonds. Crystal data: Co(HSeO3)Cl · 3 H2O, Mr = 276.40, triclinic, space group P 1 (No. 2), a = 7.1657(5) Å, b = 7.3714(5) Å, c = 7.7064(5) Å, α = 64.934(1)°, β = 68.894(1)°, γ = 71.795(1)°, V = 337.78(7) Å3, Z = 2, R(F) = 0.036, wR(F) = 0.049. Cu(HSeO3)Cl · 2 H2O, Mr = 263.00, orthorhombic, space group Pnma (No. 62), a = 9.1488(3) Å, b = 17.8351(7) Å, c = 7.2293(3) Å, V = 1179.6(2) Å3, Z = 8, R(F) = 0.021, wR(F) = 0.024. 相似文献
12.
《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
13.
Ming‐Lin Guo Chen‐Hu Guo 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(10):m342-m344
In the title complex, {[Cd2(C8H3NO6)2(C4H10N2)(H2O)4]·2H2O}n, the CdII atoms show distorted octahedral coordination. The two carboxylate groups of the dianionic 2‐nitroterephthalate ligand adopt monodentate and 1,2‐bridging modes. The piperazine molecule is in a chair conformation and lies on a crystallographic inversion centre. The CdII atoms are connected via three O atoms from two carboxylate groups and two N atoms from piperazine molecules to form a two‐dimensional macro‐ring layer structure. These layers are further aggregated to form a three‐dimensional structure via rich intra‐ and interlayer hydrogen‐bonding networks. This study illustrates that, by using the labile CdII salt and a combination of 2‐nitroterephthalate and piperazine as ligands, it is possible to generate interesting metal–organic frameworks with rich intra‐ and interlayer O—H...O hydrogen‐bonding networks. 相似文献
14.
Ana María Atria María Teresa Garland Ricardo Baggio Piedad Corts 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(7):m297-m302
Two new oxo complexes, namely hexa‐μ2‐acetato‐acetatoaquabis(di‐3‐pyridylamine)di‐μ3‐oxo‐tetrairon(III) chloride monohydrate ethanol 1.25‐solvate, [Fe4(C2H3O2)7O2(C10H9N3)2(H2O)]Cl·1.25C2H6O·H2O, (I), containing a tetranuclear [Fe4(μ3‐O)2]8+ unit, and 2‐methylimidazolium hexa‐μ2‐acetato‐acetatodiaqua‐μ3‐oxo‐triiron(III) chloride dihydrate, (C4H7N2)[Fe3(C2H3O2)7O(H2O)2]Cl·2H2O, (II), with a trinuclear [Fe3(μ3‐O)]7+ unit, are presented. Both structures are formed by two well differentiated entities, viz. a compact isolated cluster composed of FeIII ions coordinated to O2− and CH3CO2− anions, and an external group formed by a central Cl− ion surrounded by different solvent groups to which the anion is bound through hydrogen bonding. In the case of (I), charge balance cannot be achieved within the groups, so the structure is macroscopically ionic; in the case of (II), in contrast, each group is locally neutral owing to the internal compensation of charges. The trinuclear complex crystallizes with the metal cluster, chloride anion and 2‐methylimidazolium cation bisected by a crystallographic mirror plane. 相似文献
15.
Onur ahin Dursun Ali Kse Elif Fureyya Ozturkkan Hacali Necefoglu Orhan Büyükgüngr 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(6):m243-m245
The title compound, [Co(C7H4FO2)2(C6H6N2O)2(H2O)2], is a three‐dimensional hydrogen‐bonded supramolecular complex. The CoII ion resides on a centre of symmetry and is in an octahedral coordination environment comprising two pyridyl N atoms, two carboxylate O atoms and two O atoms from water molecules. Intermolecular N—H...O and O—H...O hydrogen bonds produce R32(6), R22(12) and R22(16) rings, which lead to two‐dimensional chains. An extensive three‐dimensional network of C—H...F, N—H...O and O—H...O hydrogen bonds and π–π interactions are responsible for crystal stabilization. 相似文献
16.
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
17.
John Bacsa Hanhua Zhao Kim R. Dunbar 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(12):m561-m564
Two new iron–oxo clusters, viz. di‐μ‐trifluoroacetato‐μ‐oxo‐bis[(2,2′‐bipyridine‐κ2N,N′)(trifluoroacetato‐κO)iron(III)], [Fe2O(CF3CO2)4(C10H8N2)2], and bis(2,2′‐bipyridine)di‐μ3‐oxo‐hexa‐μ‐trifluoroacetato‐bis(trifluoroacetato)tetrairon(III) trifluoroacetic acid solvate, [Fe4O2(CF3CO2)8(C10H8N2)2]·CF3CO2H, contain dinuclear and tetranuclear FeIII cores, respectively. The FeIII atoms are in distorted octahedral environments in both compounds and are linked by oxide and trifluoroacetate ions. The trifluoroacetate ions are either bridging (bidentate) or coordinated to the FeIII atoms via one O atom only. The fluorinated peripheries enhance the solubility of these compounds. Formal charges for all the Fe centers were assigned by summing valences of the chemical bonds to the FeIII atom. 相似文献
18.
Onur ahin Orhan Büyükgüngr Dursun Ali Kse Hacali Necefoglu 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(11):m510-m512
The title compound, [Cu(C7H5O3)2(C6H6N2O)2(H2O)2], is a two‐dimensional hydrogen‐bonded supramolecular complex. The CuII ion resides on a centre of symmetry and is in an octahedral coordination environment comprising two pyridine N atoms, two carboxylate O atoms and two O atoms from water molecules. Intermolecular N—H...O and O—H...O hydrogen bonds produce R22(4), R22(8) and R22(15) rings which lead to one‐dimensional polymeric chains. An extensive two‐dimensional network of N—H...O and O—H...O hydrogen bonds and C—H...π interactions are responsible for crystal stabilization. 相似文献
19.
Nobuyuki Matsushita 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(2):m33-m36
The title compound, {[PtIIPtIVI2(C2H8N2)4](HPO4)(H2PO4)I·3H2O}n, has a chain structure composed of square‐planar [Pt(en)2]2+ and elongated octahedral trans‐[PtI2(en)2]2+ cations (en is ethylenediamine) stacked alternately along the c axis and bridged by the I atoms; a three‐dimensionally valence‐ordered system exists with respect to the Pt sites. The title compound also has a unique cyclic tetramer structure composed of two hydrogenphosphate and two dihydrogenphosphate ions connected by strong hydrogen bonds [O⋯O = 2.522 (10), 2.567 (10) and 2.569 (11) Å]. The Pt and I atoms form a zigzag ⋯I—PtIV—I⋯PtII⋯ chain, with PtIV—I bond distances of 2.6997 (7) and 2.6921 (7) Å, interatomic PtII⋯I distances of 3.3239 (8) and 3.2902 (7) Å, and PtIV—I⋯PtII angles of 154.52 (3) and 163.64 (3)°. The structural parameters indicating the mixed‐valence state of platinum, expressed by δ = (PtIV—I)/(PtII—I), are 0.812 and 0.818 for the two independent I atoms. 相似文献
20.
A novel dinuclear bismuth(III) coordination compound, [Bi2(C7H3NO4)2(N3)2(C12H8N2)2]·4H2O, has been synthesized by an ionothermal method and characterized by elemental analysis, energy‐dispersive X‐ray spectroscopy, IR, X‐ray photoelectron spectroscopy and single‐crystal X‐ray diffraction. The molecular structure consists of one centrosymmetric dinuclear neutral fragment and four water molecules. Within the dinuclear fragment, each BiIII centre is seven‐coordinated by three O atoms and four N atoms. The coordination geometry of each BiIII atom is distorted pentagonal–bipyramidal (BiO3N4), with one azide N atom and one bridging carboxylate O atom located in axial positions. The carboxylate O atoms and water molecules are assembled via O—H...O hydrogen bonds, resulting in the formation of a three‐dimensional supramolecular structure. Two types of π–π stacking interactions are found, with centroid‐to‐centroid distances of 3.461 (4) and 3.641 (4) Å. 相似文献