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1.
Young‐Hwan Jeong Minjung Son Hongsik Yoon Pyosang Kim Do‐Hyung Lee Prof. Dongho Kim Prof. Woo‐Dong Jang 《Angewandte Chemie (International ed. in English)》2014,53(27):6925-6928
An artificial light‐harvesting multiporphyrin dendrimer ( 8PZnPFB ) composed of a focal freebase porphyrin ( PFB ) with eight zinc(II) porphyrin ( PZn ) wings exhibited unique photophysical property switching in response to specific guest molecule binding. UV/Vis titration studies indicated stable 1:2 host–guest complex formation between 8PZnPFB and meso‐tetrakis(4‐pyridyl)‐porphyrin ( TPyP ) for which the first and second association constants were estimated to be >108 M ?1 and 3.0×107 M ?1, respectively. 8PZnPFB originally shows 94 % energy transfer efficiency from PZn to the focal PFB . By the formation of the host–guest complex ( 8PZnPFB? 2 TPyP ) the emission intensity of 8PZnPFB is significantly decreased, and an ultrafast charge separation state is generated. The energy transfer process from PZn wings to the PFB core in 8PZnPFB is almost entirely switched to an electron transfer process by the formation of 8PZnPFB? 2 TPyP . 相似文献
2.
Yueh‐Hsuan Tsai Chia‐Her Lin Chu‐Chieh Lin Bao‐Tsan Ko 《Journal of polymer science. Part A, Polymer chemistry》2009,47(19):4927-4936
A novel tridentate anilido‐aldimine ligand, [o‐C6H4(NHAr)? HC?NCH2CH2NMe2] (Ar = 2,6‐iPr2C6H3, L ‐H, 1 ), has been prepared by the condensation of N, N‐dimethylethylenediamine with one molar equivalent of 2‐fluoro‐benzaldehyde in hexane, followed by the addition of the lithium salt of diisopropylaniline in THF. Magnesium (Mg) and zinc (Zn) complexes supported by the tridentate anilido‐aldimine ligand have been synthesized and structurally characterized. Reaction of L ‐H ( 1 ) with an equivalent amount of MgnBu2 or ZnEt2 produces the monomeric complex [ L MgnBu] ( 2 ) or [ L ZnEt] ( 3 ), respectively. Experimental results show that complexes 2 and 3 are efficient catalysts for ring‐opening polymerization of ε‐caprolactone (CL) and L ‐lactide (LA) in the presence of benzyl alcohol and catalyze the polymerization of ε‐CL and L ‐LA in a controlled fashion yielding polymers with a narrow polydispersity index. In both polymerizations, the activity of Mg complex 2 is higher than that of Zn complex 3 , which is probably due to the higher Lewis acidity and better oxophilic nature of Mg2+ metal. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4927–4936, 2009 相似文献
3.
Julia Intemann Dr. Jan Spielmann Dr. Peter Sirsch Prof. Dr. Sjoerd Harder 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(26):8478-8489
A new tetranuclear magnesium hydride cluster, [{ NN ‐(MgH)2}2], which was based on a N? N‐coupled bis‐β‐diketiminate ligand ( NN 2?), was obtained from the reaction of [{ NN ‐(MgnBu)2}2] with PhSiH3. Its crystal structure reveals an almost‐tetrahedral arrangement of Mg atoms and two different sets of hydride ions, which give rise to a coupling in the NMR spectrum (J=8.5 Hz). To shed light on the relationship between the cluster size and H2 release, the thermal decomposition of [{ NN ‐(MgH)2}2] and two closely related systems that were based on similar ligands, that is, an octanuclear magnesium hydride cluster and a dimeric magnesium hydride species, have been investigated in detail. A lowering of the H2‐desorption temperature with decreasing cluster size is observed, in line with previously reported theoretical predictions on (MgH2)n model systems. Deuterium‐labeling studies further demonstrate that the released H2 solely originates from the oxidative coupling of two hydride ligands and not from other hydrogen sources, such as the β‐diketiminate ligands. Analysis of the DFT‐computed electron density in [{ NN ‐(MgH)2}2] reveals a counterintuitive interaction between two formally closed‐shell H? ligands that are separated by 3.106 Å. This weak interaction could play an important role in H2 desorption. Although the molecular product after H2 release could not be characterized experimentally, DFT calculations on the proposed decomposition product, that is, the low‐valence tetranuclear Mg(I) cluster [( NN ‐Mg2)2], predict a structure with two almost‐parallel, localized Mg? Mg bonds. As in a previously reported β‐diketiminate MgI dimer, the Mg? Mg bond is not characterized by a bond critical point, but instead displays a local maximum of electron density midway between the atoms, that is, a non‐nuclear attractor (NNA). Interestingly, both of the NNAs in [( NN ‐Mg2)2] are connected through a bond path that suggests that there is bonding between all four MgI atoms. 相似文献
4.
Po‐Sheng Chen Yi‐Chang Liu Chia‐Her Lin Bao‐Tsan Ko 《Journal of polymer science. Part A, Polymer chemistry》2010,48(16):3564-3572
Two novel sulfonate phenol ligands—3,3′‐di‐tert‐butyl‐2′‐hydroxy‐5,5′,6,6′‐tetramethyl‐biphenyl‐2‐yl 4‐X‐benzenesulfonate (X?CF3, LCF3 ‐H, and X?OCH3, LOMe ‐H)—were prepared through the sulfonylation of 3,3′‐di‐tert‐butyl‐5,5′,6,6′‐tetramethylbiphenyl‐2,2′‐diol with the corresponding 4‐substituted benzenesulfonyl chloride (1 equiv.) in the presence of excess triethylamine. Magnesium (Mg) complexes supported by sulfonate phenoxide ligands were synthesized and characterized structurally. The reaction of MgnBu2 with L‐H (2 equiv.) produces the four‐coordinated monomeric complexes ( LCF3 )2Mg ( 1 ) and ( LOMe )2Mg ( 2 ). Complexes 1 and 2 are efficient catalysts for the ring‐opening polymerization of ε‐caprolactone (ε‐CL) and trimethylene carbonate (TMC) in the presence of 9‐anthracenemethanol; complex 1 catalyzes the polymerization of ε‐CL and TMC in a controlled manner, yielding polymers with the expected molecular weights and narrow polydispersity indices (PDIs). In ε‐CL polymerization, the activity of complex 1 is greater than that of complex 2 , likely because of the greater Lewis acidity of Mg2+ metal caused by the electron‐withdrawing substitute trifluoromethyl (? CF3) at the 4‐position of the benzenesulfonate group. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3564–3572, 2010 相似文献
5.
Dr. Irantzu Sádaba Dr. Manuel Ojeda Prof. Rafael Mariscal Prof. Ryan Richards Prof. Manuel López Granados 《Chemphyschem》2012,13(14):3282-3292
A series of Mg‐Zr mixed oxides with different nominal Mg/ (Mg+Zr) atomic ratios, namely 0, 0.1, 0.2, 0.4, 0.85, and 1, is prepared by alcogel methodology and fundamental insights into the phases obtained and resulting active sites are studied. Characterization is performed by X‐ray diffraction, transmission electron microscopy, X‐ray photoelectron spectroscopy, N2 adsorption–desorption isotherms, and thermal and chemical analysis. Cubic MgxZr1?xO2?x solid solution, which results from the dissolution of Mg2+ cations within the cubic ZrO2 structure, is the main phase detected for the solids with theoretical Mg/ (Mg+Zr) atomic ratio ≤0.4. In contrast, the cubic periclase (c‐MgO) phase derived from hydroxynitrates or hydroxy precursors predominates in the solid with Mg/(Mg+Zr)=0.85. c‐MgO is also incipiently detected in samples with Mg/(Mg+Zr)=0.2 and 0.4, but in these solids the c‐MgO phase mostly arises from the segregation of Mg atoms out of the alcogel‐derived c‐MgxZr1?xO2?x phase during the calcination process, and therefore the species c‐MgO and c‐MgxZr1?xO2?x are in close contact. Regarding the intrinsic activity in furfural–acetone aldol condensation in the aqueous phase, these Mg? O? Zr sites located at the interface between c‐MgxZr1?xO2?x and segregated c‐MgO display a much larger intrinsic activity than the other noninterface sites that are present in these catalysts: Mg? O? Mg sites on c‐MgO and Mg? O? Zr sites on c‐MgxZr1?xO2?x. The very active Mg? O? Zr sites rapidly deactivate in the furfural–acetone condensation due to the leaching of active phases, deposition of heavy hydrocarbonaceous compounds, and hydration of the c‐MgO phase. Nonetheless, these Mg‐Zr materials with very high specific surface areas would be suitable solid catalysts for other relevant reactions catalyzed by strong basic sites in nonaqueous environments. 相似文献
6.
Yaeun Kang Hui Chen Dr. Yu Jin Jeong Wenzhen Lai Dr. Eun Hae Bae Sason Shaik Prof. Dr. Wonwoo Nam Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(39):10039-10046
The proximal axial ligand in heme iron enzymes plays an important role in tuning the reactivities of iron(IV)‐oxo porphyrin π‐cation radicals in oxidation reactions. The present study reports the effects of axial ligands in olefin epoxidation, aromatic hydroxylation, alcohol oxidation, and alkane hydroxylation, by [(tmp)+. FeIV(O)(p‐Y‐PyO)]+ ( 1 ‐Y) (tmp=meso‐tetramesitylporphyrin, p‐Y‐PyO=para‐substituted pyridine N‐oxides, and Y=OCH3, CH3, H, Cl). In all of the oxidation reactions, the reactivities of 1 ‐Y are found to follow the order 1 ‐OCH3 > 1 ‐CH3 > 1 ‐H > 1 ‐Cl; negative Hammett ρ values of ?1.4 to ?2.7 were obtained by plotting the reaction rates against the σp values of the substituents of p‐Y‐PyO. These results, as well as previous ones on the effect of anionic nucleophiles, show that iron(IV)‐oxo porphyrin π‐cation radicals bearing electron‐donating axial ligands are more reactive in oxo‐transfer and hydrogen‐atom abstraction reactions. These results are counterintuitive since iron(IV)‐oxo porphyrin π‐cation radicals are electrophilic species. Theoretical calculations of anionic and neutral ligands reproduced the counterintuitive experimental findings and elucidated the root cause of the axial ligand effects. Thus, in the case of anionic ligands, as the ligand becomes a better electron donor, it strengthens the FeO? H bond and thereby enhances its H‐abstraction activity. In addition, it weakens the Fe?O bond and encourages oxo‐transfer reactivity. Both are Bell–Evans–Polanyi effects, however, in a series of neutral ligands like p‐Y‐PyO, there is a relatively weak trend that appears to originate in two‐state reactivity (TSR). This combination of experiment and theory enabled us to elucidate the factors that control the reactivity patterns of iron(IV)‐oxo porphyrin π‐cation radicals in oxidation reactions and to resolve an enigmatic and fundamental problem. 相似文献
7.
Syed Raza Shah Zarbad Shah Najeeb Ullah Javid Hussain Rashid Al-Harrasi Ajmal Khan Jeremy M. Rawson Ahmed Al-Harrasi Muhammad U. Anwar 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(3):294-303
Reactions of 1,10‐phenanthroline (phen) and 2‐(3,4‐dichlorophenyl)acetic acid (dcaH) with Mn(CO3) (M = LiI, NaI and MgII; n = 1 and 2) in MeOH yield the mononuclear lithium complex aqua[2‐(3,4‐dichlorophenyl)acetato‐κO](1,10‐phenanthroline‐κ2N,N′)lithium(I), [Li(C8H5Cl2O2)(C12H8N2)(H2O)] or [Li(dca)(phen)(H2O)] ( 1 ), the dinuclear sodium complex di‐μ‐aqua‐bis{[2‐(3,4‐dichlorophenyl)acetato‐κO](1,10‐phenanthroline‐κ2N,N′)sodium(I)}, [Na2(C8H5Cl2O2)2(C12H8N2)2(H2O)2] or [Na2(dca)2(phen)2(H2O)2] ( 2 ), and the one‐dimensional chain magnesium complex catena‐poly[[[diaqua(1,10‐phenanthroline‐κ2N,N′)magnesium]‐μ‐2‐(3,4‐dichlorophenyl)acetato‐κ2O:O′] 2‐(3,4‐dichlorophenyl)acetate monohydrate], {[Mg(C8H5Cl2O2)(C12H8N2)(H2O)2](C8H5Cl2O2)·H2O}n or {[Mg(dca)(phen)(H2O)2](dca)·H2O}n ( 3 ). In these complexes, phen binds via an N,N′‐chelate pocket, while the deprotonated dca? ligands coordinate either in a monodentate (in 1 and 2 ) or bidentate (in 3 ) fashion. The remaining coordination sites around the metal ions are occupied by water molecules in all three complexes. Complex 1 crystallizes in the triclinic space group P with one molecule in the asymmetric unit. The Li+ ion adopts a four‐coordinated distorted seesaw geometry comprising an [N2O2] donor set. Complex 2 crystallizes in the triclinic space group P with half a molecule in the asymmetric unit, in which the Na+ ion adopts a five‐coordinated distorted spherical square‐pyramidal geometry, with an [N2O3] donor set. Complex 3 crystallizes in the orthorhombic space group P212121, with one Mg2+ ion, one phen ligand, two dca? ligands and three water molecules in the asymmetric unit. Both dcaH ligands are deprotonated, however, one dca? anion is not coordinated, whereas the second dca? anion coordinates in a bidentate fashion bridging two Mg2+ ions, resulting in a one‐dimensional chain structure for 3 . The Mg2+ ion adopts a distorted octahedral geometry, with an [N2O4] donor set. Complexes 1 – 3 were evaluated against urease and α‐glucosidase enzymes for their inhibition potential and were found to be inactive. 相似文献
8.
Ekaterina S. Smirnova Anna A. Melekhova Vladislav V. Gurzhiy Stanislav I. Selivanov Dmitrii V. Krupenya Dr. Igor O. Koshevoy Prof. Dr. Sergey P. Tunik 《无机化学与普通化学杂志》2012,638(2):415-422
Reactions of [Cu(NCMe)4]+ with stoichiometric amount of diphosphine R2P–(C6H4)n–PR2, (R = NC4H4, n = 1; R = Ph, n = 1, 2, 3) or tri‐phosphine 1, 3, 5‐(PPh2–C6H4–)3–C6H3 ligands give the corresponding di‐ or trinuclear copper(I) acetonitrile‐phosphine complexes 1 – 5 . Substitution of the labile acetonitrile groups with chelating aromatic diimines – 2, 2′‐bipyridine (bpy), 1, 10‐phenanthroline (phen), 5, 6‐dimethyl‐1, 10‐phenanthroline (dmp), 5, 6‐dibromo‐1, 10‐phenanthroline (phenBr2) – gives the corresponding substituted compounds 6 – 16 . In all complexes 1 – 16 each central CuI atom has tetrahedral configuration completed with two N‐ and two P‐donor groups. The compounds obtained were characterized using elemental analysis, ESI‐MS, X‐ray crystallography, and NMR spectroscopy. All phosphine‐diimine compounds 6 – 16 are photoluminescent at room temperature both in dichloromethane solution and in solid state (λex = 385 nm). In CH2Cl2 solution the maxima of emission bands are found in a range 540–640 nm, and in solid in a similar range 538–620 nm. Emission of 6 – 16 is assigned to the triplet excited state dominated by the charge transfer transitions with contribution of the MLCT character. 相似文献
9.
Yi‐Chang Liu Chia‐Her Lin Bao‐Tsan Ko Rong‐Ming Ho 《Journal of polymer science. Part A, Polymer chemistry》2010,48(23):5339-5347
Magnesium (Mg) and zinc (Zn) complexes incorporating tridentate anilido‐aldimine ligand, (E)‐2, 6‐diisopropyl‐N‐(2‐((2‐(piperidin‐1‐yl)ethylimino)methyl)phenyl)aniline ( AA Pip ‐H, 1 ), were synthesized and structurally characterized. The reaction of AA Pip ‐H ( 1 ) with MgnBu2 or ZnEt2 in equivalent proportions afforded the monomeric complex [( AA Pip )MgnBu] ( 2 ) or [( AA Pip )ZnEt] ( 3 ), respectively. The coordination modes of these complexes differ in the solid state: Mg complex 2 shows a four‐coordinated and distorted tetrahedral geometry, whereas Zn complex 3 adopts a trigonal planar geometry with a three‐coordinated Zn center. Complexes 2 and 3 are efficient catalysts for the ring‐opening polymerization of β‐butyrolactone (β‐BL) in the presence of 9‐anthracenemethanol (9‐AnOH). The polymerization of β‐BL with the Zn catalyst system is demonstrated in a living fashion with a narrow polydispersity index, PDI = 1.01–1.10. The number‐averaged molecular weight (Mn) of the produced poly(3‐hydroxybutyrate) (PHB) is quite close to the expected Mn over diverse molar ratios of monomer to 9‐AnOH. A greater ratio of monomer to alcohol catalyzed by Zn complex 3 served to form PHB with a large molecular weight (Mn > 60000). An effective method to prepare PHB‐b‐PCL and PEG‐b‐PHB by the ring‐opening copolymerization of β‐BL catalyzed by zinc complex 3 is reported. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 相似文献
10.
Abolghasem Moghimi Robabeh Alizadeh M. Carla Aragoni Vito Lippolis Hossein Aghabozorg Parviz Norouzi Francesco Isaia Shabnam Sheshmani 《无机化学与普通化学杂志》2005,631(10):1941-1946
The novel 1,10‐phenanthroline‐2,9‐dicarboxylate containing Chromium(III) complex, (pydaH)[Cr(phendc)2] · 5H2O, was synthesized using proton‐transfer compound LH2, (pydaH2)2+(phendc)2?, (pyda: 2,6‐pyridinediamine; phendcH2: 1,10‐phenanthroline‐2,9‐dicarboxylic acid) and thoroughly characterized by elemental analysis, IR spectroscopy, X‐ray crystallography and cyclic voltammetry. The complex crystallizes in the monoclinic space group P21/n with four formula units in the unit cell. The unit cell dimensions are: a = 13.962(3) Å, b = 14.529(3) Å, c = 16.381(3) Å and β = 106.691(4)°. In this complex, 1,10‐phenanthroline‐2,9‐dicarboxylate acts as a tridentate ligand and the lattice is composed of anionic hexacoordinated complex, [Cr(phendc)2]?, 2,6‐pyridiniumdiamine counter ion, (pydaH)+, and five lattice water molecules. Crystallographic characterization revealed that the resulting supramolecular structure is strongly stabilized by complicated network of hydrogen bonds between the crystallization water molecules, counter ion and both coordinated and uncoordinated carboxylate groups. There is no relevant π‐π interaction for this anionic complex between pyda or phendc moieties. The electrochemical studies indicated over potential for both the cathodic and anodic peaks of the complex with respect to the free Cr3+ ion, as a consequence of the energy requirement for rearrangement of the ligand at electrode surface. 相似文献
11.
Yu‐Xiu Jin Fang Yang Li‐Min Yuan Chao‐Guo Yan Wen‐Long Liu 《Acta Crystallographica. Section C, Structural Chemistry》2014,70(5):517-521
In poly[[μ3‐2,2′‐(disulfanediyl)dibenzoato‐κ5O:O,O′:O′′,O′′′](1,10‐phenanthroline‐κ2N,N′)cadmium(II)], [Cd(C14H8O4S2)(C12H8N2)]n, the asymmetric unit contains one CdII cation, one 2,2′‐(disulfanediyl)dibenzoate anion (denoted dtdb2−) and one 1,10‐phenanthroline ligand (denoted phen). Each CdII centre is seven‐coordinated by five O atoms of bridging/chelating carboxylate groups from three dtdb2− ligands and by two N atoms from one phen ligand, forming a distorted pentagonal–bipyramidal geometry. The CdII cations are bridged by dtdb2− anions to give a two‐dimensional (4,4) layer. The layers are stacked to generate a three‐dimensional supramolecular architecture via a combination of aromatic C—H...π and π–π interactions. The thermogravimetric and luminescence properties of this compound were also investigated. 相似文献
12.
Alkali‐Metal‐Mediated Magnesiations of an N‐Heterocyclic Carbene: Normal,Abnormal, and “Paranormal” Reactivity in a Single Tritopic Molecule
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Dr. Antonio J. Martínez‐Martínez Dr. M. Ángeles Fuentes Dr. Alberto Hernán‐Gómez Prof. Eva Hevia Dr. Alan R. Kennedy Prof. Robert E. Mulvey Dr. Charles T. O'Hara 《Angewandte Chemie (International ed. in English)》2015,54(47):14075-14079
Herein the sodium alkylmagnesium amide [Na4Mg2(TMP)6(nBu)2] (TMP=2,2,6,6‐tetramethylpiperidide), a template base as its deprotonating action is dictated primarily by its 12 atom ring structure, is studied with the common N‐heterocyclic carbene (NHC) IPr [1,3‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene]. Remarkably, magnesiation of IPr occurs at the para‐position of an aryl substituent, sodiation occurs at the abnormal C4 position, and a dative bond occurs between normal C2 and sodium, all within a 20 atom ring structure accommodating two IPr2?. Studies with different K/Mg and Na/Mg bimetallic bases led to two other magnesiated NHC structures containing two or three IPr? monoanions bound to Mg through abnormal C4 sites. Synergistic in that magnesiation can only work through alkali‐metal mediation, these reactions add magnesium to the small cartel of metals capable of directly metalating a NHC. 相似文献
13.
Masataka Ohtani Kenji Saito Shunichi Fukuzumi Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(36):9160-9168
Cup‐shaped nanocarbons (CNC) generated by the electron‐transfer reduction of cup‐stacked carbon nanotubes have been functionalized with porphyrins (H2P) as light‐capturing chromophores. The resulting donor–acceptor nanohybrid has been characterized by thermogravimetric analysis (TGA), Raman and IR spectroscopy, transmission electron microscopy, elemental analysis, and UV/Vis spectroscopy. The weight of the porphyrins attached to the cup‐shaped nanocarbons was determined as 20 % by TGA and elemental analysis. The UV/Vis absorption spectrum of CNC? (H2P)n in DMF agrees well with that obtained by the superposition of reference porphyrin (ref‐H2P) and cup‐shaped nanocarbons. The photoexcitation of the CNC? (H2P)n nanohybrid results in formation of the charge‐separated (CS) state to attain the longest CS lifetime (0.64±0.01 ms) ever reported for donor–acceptor nanohybrids, which may arise from efficient electron migration following the charge separation. The formation of a radical ion pair was detected directly by electron spin resonance (ESR) measurements under photoirradiation of CNC? (H2P)n with a high‐pressure mercury lamp in frozen DMF at 153 K. The observed ESR signal at g=2.0044 agrees with that of ref‐H2P.+ produced by one‐electron oxidation with [Ru(bpy)3]3+ in deaerated CHCl3, indicating the formation of H2P.+. The electron‐acceptor ability of the reference CNC compound (ref‐CNC) was also examined by the electron‐transfer reduction of ref‐CNC by a series of semiquinone radical anions. 相似文献
14.
catena‐Poly[[bis[aqua(1,10‐phenanthroline)lead(II)]‐di‐μ3‐5‐carboxy‐3‐sulfonatobenzoato] dihydrate]
Mao‐Lin Hu Xin‐Hua Li Hong‐Ping Xiao Qiao Zhang 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(3):m130-m132
In the centrosymmetric title polymer, catena‐poly[[bis[aqua(1,10‐phenanthroline‐κ2N,N′)lead(II)]‐di‐μ3‐5‐carboxy‐3‐sulfonatobenzoato‐1:2:1′κ4O3:O1,O1′:O1;2′:1:2κ4O1:O1,O1′:O3] dihydrate], {[Pb(C8H4O7S)(C12H8N2)(H2O)]·H2O}n, each seven‐coordinate lead(II) ion is bound by five O atoms from one water molecule and three 5‐sulfoisophthalate (sip) anions, and by two N atoms from a 1,10‐phenanthroline (phen) ligand. The sip sulfonate group is monodentate. One O atom of the sip carboxylate group is chelated to one Pb2+ cation, with the other also bridging an adjacent Pb2+ cation. The carboxyl group is uncoordinated. This unusual coordination results in a chain structure along the b axis, which is linked by strong intermolecular hydrogen bonds into a three‐dimensional network. 相似文献
15.
Chihiro Maeda Pyosang Kim Sung Cho Jong Kang Park Jong Min Lim Dongho Kim Prof. Dr. Josh Vura‐Weis Michael R. Wasielewski Prof. Dr. Hiroshi Shinokubo Prof. Dr. Atsuhiro Osuka Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(17):5052-5061
meso‐Triazolyl‐appended ZnII–porphyrins were readily prepared by CuI‐catalyzed 1,3‐dipolar cycloaddition of benzyl azide to meso‐ethynylated ZnII–porphyrin (click chemistry). In noncoordinating CHCl3 solvent, spontaneous assembly occurred to form tetrameric array ( 3 )2 from meso–meso‐linked diporphyrins 3 , and dodecameric porphyrin squares ( 4 )4 and ( 5 )4 from the L ‐shaped meso–meso‐linked triporphyrins 4 and 5 . The structures of these assemblies were examined by 1H NMR spectra, absorption spectra, and their gel permeation chromatography (GPC) retention time. Furthermore, the structures of the dodecameric porphyrin squares ( 4 )4 and ( 5 )4 were probed by small‐ and wide‐angle X‐ray scattering (SAXS/WAXS) measurements in solution using a synchrotron source. Excitation‐energy migration processes in these assemblies were also investigated in detail by using both steady‐state and time‐resolved spectroscopic methods, which revealed efficient excited‐energy transfer (EET) between the meso–meso‐linked ZnII–porphyrin units that occurred with time constants of 1.5 ps?1 for ( 3 )2 and 8.8 ps?1 for ( 5 )4. 相似文献
16.
Mao‐Lin Hu Hong‐Ping Xiao Ji‐Xin Yuan 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(3):m112-m113
In the title compound, poly[[aqua(1,10‐phenanthroline)cobalt(II)]‐μ4‐dihydrogen benzene‐1,2,4,5‐tetracarboxylato], [Co(C10H4O8)(C12H8N2)(H2O)]n, each cobalt(II) cation has an octahedral geometry completed by one aqua O atom, three carboxy O atoms belonging to three H2TCB2− anions (H2TCB2− is dihydrogen benzene‐1,2,4,5‐tetracarboxylate) and two N atoms from a 1,10‐phenanthroline molecule. In the asymmetric unit, there are two half H2TCB2− anions lying about independent inversion centres. The bridging H2TCB2− anions have two coordination modes, viz.μ2‐H2TCB2− and μ4‐H2TCB2−, resulting in a two‐dimensional coordination polymer. Furthermore, a three‐dimensional network is formed by Ocarboxy⋯Ocarboxy hydrogen‐bond interactions, with H⋯A distances in the range 1.69–1.82 Å, and Ocarboxy⋯Owater interactions, with H⋯A distances in the range 1.91–1.94 Å. 相似文献
17.
Xin‐Hua Li Sai‐Zhen Yang 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(9):m423-m425
In the title centrosymmetric dimer, [Pb2(sbc)2(phen)2]·2H2O [sbc is the 2‐sulfonatobenzoate dianion (C7H4O5S) and phen is 1,10‐phenanthroline (C12H8N2)], each PbII ion is six‐coordinated by four O atoms, viz. carboxylate and sulfonate O atoms from two sbc anions, and two N atoms from a 1,10‐phenanthroline ligand. One 1,10‐phenanthroline ligand and the carboxylate group of one sbc ligand are chelated to each PbII cation, and the sulfonate group of the other sbc unit is monodentate. One O atom of the chelated carboxylate group also bridges to the other PbII cation, so that each pair of PbII ions is bridged by two sbc anions and has the same coordination environment, forming a dinuclear ring. Each pair of PbII ions is thus connected by two different kinds of bridges, namely a carboxylate short bridge and a carboxylate–sulfonate long bridge. There is also a special position of site symmetry at the centre of the two PbII cations. 相似文献
18.
Dr. Mohamed E. El‐Khouly Dr. Channa A. Wijesinghe Dr. Vladimir N. Nesterov Prof. Melvin E. Zandler Prof. Shunichi Fukuzumi Prof. Francis D'Souza 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(43):13844-13853
New multi‐modular donor–acceptor conjugates featuring zinc porphyrin (ZnP), catechol‐chelated boron dipyrrin (BDP), triphenylamine (TPA) and fullerene (C60), or naphthalenediimide (NDI) have been newly designed and synthesized as photosynthetic antenna and reaction‐center mimics. The X‐ray structure of triphenylamine‐BDP is also reported. The wide‐band capturing polyad revealed ultrafast energy‐transfer (kENT=1.0×1012 s?1) from the singlet excited BDP to the covalently linked ZnP owing to close proximity and favorable orientation of the entities. Introducing either fullerene or naphthalenediimide electron acceptors to the TPA‐BDP‐ZnP triad through metal–ligand axial coordination resulted in electron donor–acceptor polyads whose structures were revealed by spectroscopic, electrochemical and computational studies. Excitation of the electron donor, zinc porphyrin resulted in rapid electron‐transfer to coordinated fullerene or naphthalenediimide yielding charge separated ion‐pair species. The measured electron transfer rate constants from femtosecond transient spectral technique in non‐polar toluene were in the range of 5.0×109–3.5×1010 s?1. Stabilization of the charge‐separated state in these multi‐modular donor–acceptor polyads is also observed to certain level. 相似文献
19.
Mao‐Lin Hu Hong‐Ping Xiao Shun Wang Xin‐Hua Li 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(11):m454-m455
In the title compound, [Cu(C10H4O8)(C12H8N2)]n, the CuII cation has a four‐coordination environment completed by two N atoms from one 1,10‐phenanthroline (phen) ligand and two O atoms belonging to two dihydrogen benzene‐1,2,4,5‐tetracarboxylate anions (H2TCB2−). There is a twofold axis passing through the CuII cation and the centre of the phen ligand. The [Cu(phen)]2+ moieties are bridged by H2TCB2− anions to form an infinite one‐dimensional coordination polymer with a zigzag chain structure along the c axis. A double‐chain structure is formed by hydrogen bonds between adjacent zigzag chains. Furthermore, there are π–π stacking interactions between the phen ligands, with an average distance of 3.64 Å, resulting in a two‐dimensional network structure. 相似文献
20.
Choudhury M. Zakaria George Ferguson Alan J. Lough Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(4):o204-o208
The adduct 1,6‐diaminohexane–1,1,1‐tris(4‐hydroxyphenyl)ethane (1/2) is a salt {hexane‐1,6‐diyldiammonium–4‐[1,1‐bis(4‐hydroxyphenyl)ethyl]phenolate (1/2)}, C6H18N22+·2C20H17O3?, in which the cation lies across a centre of inversion in space group P. The anions are linked by two short O—H?O hydrogen bonds [H?O 1.74 and 1.76 Å, O?O 2.5702 (12) and 2.5855 (12) Å, and O—H?O 168 and 169°] into a chain containing two types of R(24) ring. Each cation is linked to four different anion chains by three N—H?O hydrogen bonds [H?O 1.76–2.06 Å, N?O 2.6749 (14)–2.9159 (14) Å and N—H?O 156–172°]. In the adduct 2,2′‐bipyridyl–1,1,1‐tris(4‐hydroxyphenyl)ethane (1/2), C10H8N2·2C20H18O3, the neutral diamine lies across a centre of inversion in space group P21/n. The tris(phenol) molecules are linked by two O—H?O hydrogen bonds [H?O both 1.90 Å, O?O 2.7303 (14) and 2.7415 (15) Å, and O—H?O 173 and 176°] into sheets built from R(38) rings. Pairs of tris(phenol) sheets are linked via the diamine by means of a single O—H?N hydrogen bond [H?N 1.97 Å, O?N 2.7833 (16) Å and O—H?N 163°]. 相似文献