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1.
[Cu(II)(4,4′-dimethyl-2,2′-bipyridine)3](PF6)2 ( 2 ) and [Cu(II) (5,5′-dimethyl-2,2′-bipyridine)3](PF6)2 ( 4 ) were used together with aluminium isopropoxide and (1-bromoethyl)benzene in the controlled radical polymerization of styrene resulting in polystyrenes with predetermined molecular weight and narrow molecular weight distribution. The received polymers are colorless with a content of copper lower than 210 ppm. The substitution pattern at the bipyridine ligands has a distinct influence on the polymerization. The rate of polymerization of styrene using 2 /[(CH3)2CHO]3Al/C6H5CH(CH3)Br is two times larger than utilizing 4 /[(CH3)2CHO]3Al/C6H5CH(CH3)Br.  相似文献   

2.
The single‐crystal X‐ray structures of dimethyl 2,2′‐bipyridine‐6,6′‐dicarboxylate, C14H12N2O4, and the copper(I) coordination complex bis(dimethyl 2,2′‐bipyridine‐6,6′‐dicarboxylato‐κ2N,N′)copper(I) tetrafluoroborate, [Cu(C14H12N2O4)2]BF4, are reported. The uncoordinated ligand crystallizes across an inversion centre and adopts the anticipated anti pyridyl arrangement with coplanar pyridyl rings. In contrast, upon coordination of copper(I), the ligand adopts an arrangement of pyridyl donors facilitating chelating metal coordination and an increased inter‐pyridyl twisting within each ligand. The distortion of each ligand contrasts with comparable copper(I) complexes of unfunctionalized 2,2′‐bipyridine.  相似文献   

3.
We report the efficient construction of cyclic hybrids of 2,2′-bipyridine and acetylenosaccharides from readily available building blocks involving a double Castro-Stephens coupling of an O-protected and an O-unprotected, mono-C-silylated 1,4-cis-diethynylated 1,5-anhydroglucitol (see 2 and 6 , resp.) to 6,6′-dibromo-2,2′-bipyridine ( 1 ) followed by oxidative cyclization of the resulting dialkynes (see Scheme). UV Spectra of the C-alkynylated linear and cyclized bipyridines 8 and 10 show that these ligands complex a range of metal ions (Figs. 4 and 5).  相似文献   

4.
The condensation reaction of 2,2′‐diamino‐4,4′‐dimethyl‐6,6'‐dibromo‐1,1′‐biphenyl with 2‐hydroxybenzaldehyde as well as 5‐methoxy‐, 4‐methoxy‐, and 3‐methoxy‐2‐hydroxybenzaldehyde yields 2,2′‐bis(salicylideneamino)‐4,4′‐dimethyl‐6,6′‐dibromo‐1,1′‐biphenyl ( 1a ) as well as the 5‐, 4‐, and 3‐methoxy‐substituted derivatives 1b , 1c , and 1d , respectively. Deprotonation of substituted 2,2′‐bis(salicylideneamino)‐4,4′‐dimethyl‐1,1′‐biphenyls with diethylzinc yields the corresponding substituted zinc 2,2′‐bis(2‐oxidobenzylideneamino)‐4,4′‐dimethyl‐1,1′‐biphenyls ( 2 ) or zinc 2,2′‐bis(2‐oxidobenzylideneamino)‐4,4′‐dimethyl‐6,6′‐dibromo‐1,1′‐biphenyls ( 3 ). Recrystallization from a mixture of CH2Cl2 and methanol can lead to the formation of methanol adducts. The methanol ligands can either bind as Lewis base to the central zinc atom or as Lewis acid via a weak O–H ··· O hydrogen bridge to a phenoxide moiety. Methanol‐free complexes precipitate as dimers with central Zn2O2 rings.  相似文献   

5.
6,6′‐Dimethoxygossypolone (systematic name: 7,7′‐dihydroxy‐5,5′‐diisopropyl‐6,6′‐dimethoxy‐3,3′‐dimethyl‐1,1′,4,4′‐tetraoxo‐2,2′‐binaphthalene‐8,8′‐dicarbaldehyde), C32H30O10, is a dimeric molecule formed by oxidation of 6,6′‐dimethoxygossypol. When crystallized from acetone, 6,6′‐dimethoxygossypolone has monoclinic (P21/c) symmetry, and there are two molecules within the asymmetric unit. Of the four independent quinoid rings, three display flattened boat conformations and one displays a flattened chair/half‐chair conformation. The angles between the planes of the two bridged naphthoquinone structures are fairly acute, with values of about 68 and 69°. The structure has several intramolecular O—H...O and C—H...O hydrogen bonds and several weak intermolecular C—H...O hydrogen bonds, but no intermolecular O—H...O hydrogen bonds.  相似文献   

6.
The title compound, [Pd2(C4H13N3)2(C14H16N2)](NO3)4, comprises discrete tetracationic dumbbell‐type dinuclear complex molecules and noncoordinating nitrate anions. Two Pd(dien)2+ moieties (dien is diethylenetriamine) are joined by the rigid linear exo‐bidentate bridging 2,2′,6,6′‐tetramethyl‐4,4′‐bipyridine ligand to form the dinuclear complex, which lies across a centre of inversion in the space group P21/n, so that the rings in the 2,2′,6,6′‐tetramethyl‐4,4′‐bipyridine bridging ligand are parallel. In the crystal, the primary and secondary amino groups of the dien ligand act as hydrogen‐bond donors towards the nitrate anions to form a three‐dimensional hydrogen‐bond network.  相似文献   

7.
Two new coordination polymers, {[Cd2(btc)(2,2′‐bpy)2] · H2O}n ( 1 ) and [Zn2(btc)(2,2′‐bpy)(H2O)]n ( 2 ) (H4btc = biphenyl‐2,2′,4,4′‐tetracarboxylic acid, 2,2′‐bpy = 2,2′‐bipyridine), were synthesized hydrothermally under similar conditions and characterized by elemental analysis, IR spectra, TGA, and single‐crystal X‐ray diffraction analysis. In complexes 1 and 2 , the (btc)4– ligand acts as connectors to link metal ions to give a 2D bilayer network of 1 and a 3D metal‐organic framework of 2 , respectively. The differences in the structures are induced by diverging coordination modes of the (btc)4– ligand, which can be attributed to the difference metal ions in sizes. The results indicate that metal ions have significant effects on the formation and structures of the final complexes. Additionally, the fluorescent properties of the two complexes were also studied in the solid state at room temperature.  相似文献   

8.
Atom transfer polymerization of styrene using N-aryl-substituted pyridinimines and N,N′-diaryl-substituted diimines as N,N′-ligands in the presence of Cu(I)Br and 1-phenylethyl bromide has been investigated and compared with the analogous 2,2′-bipyridine system. A molar mass increase which is consistent for a controlled polymerization with a target molar mass of 10000 g · mol−1 is observed with the 2,2′-bipyridine ( 1 ) and the pyridinimine ( 2a ) systems. The polymerization of styrene with the N,N′-diimine system ( 3 ) is much less controlled, yielding polymers with higher molar masses than expected.  相似文献   

9.
Two enantiopure palladium(II) complexes, viz. [1,1′‐(butane‐1,3‐diyl)‐3,3′,4,4′‐tetramethyl‐5,5′‐diphenyl‐2,2′‐biphosphole]dichloridopalladium(II) dichloromethane solvate [systematic name: dichlorido(1,2,5,10,11‐pentamethyl‐3,9‐diphenylperhydrodicyclopenta[a,c][1,4]diphosphepine‐κ2P,P′)palladium(II) dichloromethane solvate], [PdCl2(C28H30P2)]·CH2Cl2, have been synthesized from stereodynamic diphosphines derived from 2,2′‐biphosphole through a metal kinetic dynamic resolution. In both structures, the coordination around the metal atom is square planar, with a cis arrangement of the ligands that drastically reduces the dihedral angle between the two phosphole rings compared with the free ligand. The structural determination of both enantiomers unambiguously establishes the absolute configuration of both central and axial elements of chirality of the 2,2′‐biphosphole framework and indicates that the original carbon chirality of the backbone controls the chiralities of the 2,2′‐biphosphole framework.  相似文献   

10.
In the crystal structures of four thiophene derivatives, (E)‐3′‐[2‐(anthracen‐9‐yl)ethenyl]‐2,2′:5′,2′′‐terthiophene, C28H18S3, (E)‐3′‐[2‐(1‐pyrenyl)ethenyl]‐2,2′:5′,2′′‐terthiophene, C30H18S3, (E)‐3′‐[2‐(3,4‐dimethoxyphenyl)ethenyl]‐2,2′:5′,2′′‐terthiophene, C22H18O2S3, and (E,E)‐1,4‐bis[2‐(2,2′:5′,2′′‐terthiophen‐3′‐yl)ethenyl]‐2,5‐dimethoxybenzene, C36H26O2S6, at least one of the terminal thiophene rings is disordered and the disorder is of the flip type. The terthiophene fragments are far from being coplanar, contrary to terthiophene itself. The central C—C=C—C fragments are almost planar but the bond lengths suggest slight delocalization within this fragment. The crystal packing is determined by van der Waals interactions and some weak, relatively short, C—H...S and C—H...π directional contacts.  相似文献   

11.
Electron delocalization of new mixed‐valent (MV) systems with the aid of lateral metal chelation is reported. 2,2′‐Bipyridine (bpy) derivatives with one or two appended di‐p‐anisylamino groups on the 5,5′‐positions and a coordinated [Ru(bpy)2] (bpy=2,2′‐bipyridine), [Re(CO)3Cl], or [Ir(ppy)2] (ppy=2‐phenylpyridine) component were prepared. The single‐crystal molecular structure of the bis‐amine ligand without metal chelation is presented. The electronic properties of these complexes were studied and compared by electrochemical and spectroscopic techniques and DFT/TDDFT calculations. Compounds with two di‐p‐anisylamino groups were oxidized by a chemical or electrochemical method and monitored by near‐infrared (NIR) absorption spectral changes. Marcus–Hush analysis of the resulting intervalence charge‐transfer transitions indicated that electron coupling of these mixed‐valent systems is enhanced by metal chelation and that the iridium complex has the largest coupling. TDDFT calculations were employed to interpret the NIR transitions of these MV systems.  相似文献   

12.
The PbII cation in the title compound, [Pb2(C14H4N2O8)]n, is seven‐coordinated by one N atom and six O atoms from four 4,4′‐bipyridine‐2,2′,6,6′‐tetracarboxylate (BPTCA4−) ligands. The geometric centre of the BPTCA4− anion lies on an inversion centre. Each pyridine‐2,6‐dicarboxylate moiety of the BPTCA4− ligand links four PbII cations via its pyridyl N atom and two carboxylate groups to form two‐dimensional sheets. The centrosymmetric BPTCA4− ligand then acts as a linker between the sheets, which results in a three‐dimensional metal–organic framework.  相似文献   

13.
The bulk atom transfer radical polymerization (ATRP) of styrene or methyl acrylate was carried out in the presence of CuCl or CuBr complexed by equimolar amounts of 2,2′: 6′,2″-terpyridines (tpy) as ligands. Uncontrolled reactions were observed in the presence of unsubstituted ligands whereas relatively fast but controlled polymerization of styrene and methyl acrylate was observed for CuCl and CuBr complexed by tpy with three 5-nonyl substituents (tNtpy). Molecular weights evolved linearly with conversion and polymers with relatively low polydispersities were formed (Mw/Mn < 1.2).  相似文献   

14.
Novel conjugated polymers composed of benzo[1,2‐b:4,5‐b′]dithiophene and thieno[3,4‐b]pyrazine or dithieno[3′,2′:3,4;2″,3″:5,6]benzo[1,2‐d]imidazole units are synthesized by Stille polycondensation. The resulting polymers display a longer wavelength absorption and well‐defined redox activities. The effective intramolecular charge‐transfer and energy levels of all polymers are elucidated by computational calculations. Bulk‐heterojunction solar cells based on these polymers as p‐type semiconductors and [6,6]‐phenyl‐C61‐butyric acid methyl ester (PC61BM) as an n‐type semiconductor are fabricated, and their photovoltaic performances are for the first time evaluated. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 1067–1075  相似文献   

15.
The molecular structures of trichlorido(2,2′:6′,2′′‐terpyridine‐κ3N,N′,N′′)gallium(III), [GaCl3(C15H11N3)], and tribromido(2,2′:6′,2′′‐terpyridine‐κ3N,N′,N′′)gallium(III), [GaBr3(C15H11N3)], are isostructural, with the GaIII atom displaying an octahedral geometry. It is shown that the Ga—N distances in the two complexes are the same within experimental error, in contrast to expected bond lengthening in the bromide complex due to the lower Lewis acidity of GaBr3. Thus, masking of the Lewis acidity trends in the solid state is observed not only for complexes of group 13 metal halides with monodentate ligands but for complexes with the polydentate 2,2′:6′,2′′‐terpyridine donor as well.  相似文献   

16.
Novel EuIII complexes with bidentate phosphine oxide ligands containing a bipyridine framework, i.e., [3,3′‐bis(diphenylphosphoryl)‐2,2′‐bipyridine]tris(hexafluoroacetylacetonato)europium(III) ([Eu(hfa)3(BIPYPO)]) and [3,3′‐bis(diphenylphosphoryl)‐6,6′‐dimethyl‐2,2′‐bipyridine]tris(hexafluoroacetylacetonato)europium(III) ([Eu(hfa)3(Me‐BIPYPO)]), were synthesized for lanthanide‐based sensor materials having high emission quantum yields and effective chemosensing properties. The emission quantum yields of [Eu(hfa)3(BIPYPO)] and [Eu(hfa)3(Me‐BIPYPO)] were 71 and 73%, respectively. Metal‐ion sensing properties of the EuIII complexes were also studied by measuring the emission spectra of EuIII complexes in the presence of ZnII or CuII ions. The metal‐ion sensing and the photophysical properties of luminescent EuIII complexes with a bidentate phosphine oxide containing 2,2′‐bipyridine framework are demonstrated for the first time.  相似文献   

17.
Poly[bis(3,3′,5,5′‐tetramethyl‐4,4′‐bi‐1H‐pyrazole‐2,2′‐diium) γ‐octamolybdate(VI) dihydrate], {(C10H16N4)2[Mo8O26]·2H2O}n, (I), and bis(3,3′,5,5′‐tetramethyl‐4,4′‐bi‐1H‐pyrazole‐2,2′‐diium) α‐dodecamolybdo(VI)silicate tetrahydrate, (C10H16N4)2[SiMo12O40]·4H2O, (II), display intense hydrogen bonding between the cationic pyrazolium species and the metal oxide anions. In (I), the asymmetric unit contains half a centrosymmetric γ‐type [Mo8O26]4− anion, which produces a one‐dimensional polymeric chain by corner‐sharing, one cation and one water molecule. Three‐centre bonding with 3,3′,5,5′‐tetramethyl‐4,4′‐bi‐1H‐pyrazole‐2,2′‐diium, denoted [H2Me4bpz]2+ [N...O = 2.770 (4)–3.146 (4) Å], generates two‐dimensional layers that are further linked by hydrogen bonds involving water molecules [O...O = 2.902 (4) and 3.010 (4) Å]. In (II), each of the four independent [H2Me4bpz]2+ cations lies across a twofold axis. They link layers of [SiMo12O40]4− anions into a three‐dimensional framework, and the preferred sites for pyrazolium/anion hydrogen bonding are the terminal oxide atoms [N...O = 2.866 (6)–2.999 (6) Å], while anion/aqua interactions occur preferentially viaμ2‐O sites [O...O = 2.910 (6)–3.151 (6) Å].  相似文献   

18.
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   

19.
Two transition metal‐organic coordination polymers, [Mn2(1,3‐bdc)2(Me2bpy)2] · Me2bpy ( 1 ) and [Co(4,4′‐oba)(Me2bpy)] ( 2 ) were hydrothermally synthesized and structurally characterized by elemental analysis, IR spectroscopy, TG, and single‐crystal X‐ray diffraction [1,3‐H2bdc = benzene‐1,3‐dicarboxylic acid, H2oba = 4,4′‐oxybis(benzoic acid) Me2bpy = 4,4′‐dimethyl‐2,2′‐bipyridine]. Compound 1 crystallizes in the orthorhombic system, space group P212121, with a = 23.371(5), b = 14.419(3), and c = 14.251(3) Å. Compound 2 crystallizes in the monoclinic system, space group P21/c, with a = 7.4863(15), b = 18.272(4), c = 16.953(5) Å, and β = 107.44(3)°. The crystal structure of complex 1 is a wave‐like layer with central Mn2+ atoms bridged by 1,3‐bdc ligands, whereas the structure of compound 2 presents a ladder chain of hexacoordinate Co2+ atoms, in which the metal atoms are bridged by 4,4′‐oba ligands and decorated by Me2bpy ligands. The two compounds are further extended into 3D supramolecular structures through π–π stacking interactions. Additionally, the compounds show intense fluorescence in solid state at room temperature.  相似文献   

20.
5,5′-Bi-5H-cyclopenta[2,1-b;3,4-b′]dipyridinylidene( 1 ) was synthesized in three steps from 9,10-phenanthroline and characterized by UV/VIS and NMR spectroscopy, mass spectrometry, and cyclic voltammetry. Its ability to act as a bridging ligand is demonstrated by the synthesis of the complexes [Ru(bpy)2( 1 )](PF6)2 ( 6 ) and [{Ru(bpy)2}2( 1 )](PF6)4 ( 7 ) (bpy = 2,2′-bipyridine).  相似文献   

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