Syntheses, Characterization and Crystal Structures of Two-dimensional 4,4′-Bipyridyl Lead Halides, PbI_2(4,4′-bpy) and PbBr_2(4,4′-bpy)

IntroductionLinear bidentate N,N′- donor complexes havebeen extensively used in recent years to obtain thepolymeric frameworks with potential applicationprospects in different areas of material sciences,such as electrical conductivity[1] ,magnetism[2 ] ,photomechanical behaviour[3 ] and catalysis[4～ 6] .Among them,4,4′- bipyridine( bpy) has beenproven to be able to form one- dimensional poly-mers[7] ,two- dimensional layers[4] ,and three- di-mensional frameworks exhibiting the interpene-tra…     

Synthesis of new 4,4′-bis(arylethynyl)benzophenones and 4,4′-bis(arylglyoxalyl)benzophenones based on chloral

4,4-Diiodobenzophenone was obtained by a three-stage synthesis from chloral and iodobenzene. 4,4-Bis(arylethynyl)benzophenones were synthesized by cross-coupling of 4,4-diiodobenzophenone with terminal arylethynes in the presence of a complex Pd catalyst; further oxidation of the products obtained in an iodine/DMSO medium afforded new bis(arylglyoxalyl)benzophenones.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 670–672, March, 1996.     

Bis(β-alaninium) biphenyl-4,4′-disulfonate

In the crystal structure of the title compound, 2C₃H₈NO₂⁺·C₁₂H₈O₆S₂²⁻, N—H⃛O hydrogen bonds formed between the amino H atoms and the sulfonate O atoms give rise to the assembly of cationic β-alaninium dimers and centrosymmetric bi­phenyl-4,4′-­di­sulfonate anions into an extended two-dimensional layer. The resulting hydrogen-bonded ribbons can be described as C(6)R(12) according to graph-set notation. C—H⃛O hydrogen bonds between adjacent sheets further extend the structure into a three-dimensional arrangement.     

4,4′-Bipyridine complexes of molybdenum(II) and tungsten(II)

Treatment of [MI₂(CO)₃(NCMe)₂] with two equivalents of 4,4-bipyridine (4,4-bipy) in CH₂Cl₂ at room temperature gave the MeCN displaced products, [MI₂(CO)₃(4,4-bipy-N)₂] (1) and (2). Equimolar amounts of [MI₂(CO)₃(NCMe)₂] and L (L = PPh₃, AsPh₃ or SbPh₃) react to give [MI₂(CO)₃(NCMe)L], which when reacted in situ with 4,4-bipy yield the new complexes, [MI₂(CO)₃(4,4-bipy-N)L] (3)–(8). Reaction of equimolar quantities of [WI₂(CO)(NCMe)( ²-RC₂R)₂] (R = Me or Ph) and 4,4-bipy gave the new bis(alkyne) complexes, [WI₂(CO)(4,4-bipy-N)( ²-RC₂R)₂] (9) and (10). Treatment of [MI₂(CO)₃(NCMe)₂] with two equivalents of (9) or (10) in CH₂Cl₂ at room temperature affords the bimetallic complexes, [MI₂(CO)₃{WI₂(CO)(4,4-bipy-N,N)( ²-RC₂R)₂}₂] (11)–(14). Equimolar quantities of [MI₂(CO)₃(NCMe)(PPh₃)] (prepared in situ) and (9) or (10), react to give the 4,4-bipy-bridged complexes, [MI₂(CO)₃{WI₂(CO)(4,4-bipy-N,N)( ²-RC₂R)₂}(PPh₃)] (15)–(18). All the new complexes, (1)–(18) were characterised by elemental analysis (C, H and N), i.r. and ¹H-n.m.r. spectroscopy.     

Synthesis of 4,4′-bis(dichloroamino)- and 4,4′-bis(chloroamino)-3,3′-azofurazans,the first representatives of dichloroamino- and chloroaminofurazans

First representatives of dichloroamino- and chloroaminofurazans, viz., 4,4′-bis(dichloroamino)- and 4,4′-bis(chloroamino)-3,3′-azofurazans, were synthesized by the chlorination of 4,4′-diamino-3,3′-azofurazan with sodium hypochlorite in the CH₂Cl₂—H₂O mixture.     

4,4′-喹啉酸锌(Ⅱ)配位聚合物

Hydrothermal treatment of racemic atropisomeric ligand diethyl (R,S)-7,7′-dimethyl-4,4′-biquinoline-3,3′-dicarboxylate (DDBD) in the presence of pyridine over 4 days at 140 ℃ with Zn(OAc)₂ offers zinc coordination polymer [{Zn(DBD)(pyridine)₂(H₂O)}_n{Zn(DBD)(H₂O)_1/2}]_n (1), which shows weak fluorescence at about 490 nm at solid state at room temperature. CCDC: 631007.     

Thermal Decomposition of (4,4′-Dimethyl-2,2′-Bipyridine) Tris(Benzoate) Europium(III): Non-isothermal kinetics

The thermal behavior of[Eu₂(BA)₆(dmbpy)₂] (BA=C₇H₅O ₂ ^– , benzoate; dmbpy=C₁₂H₁₂N₂, 4,4-dimethyl-2,2-bipyridine) and its kinetics were studied under the non-isothermal condition in a static air atmosphere by TG-DTG, IR and SEM methods. Thermal decomposition of [Eu₂(BA)₆(dmbpy)₂] occurred in four consecutive stages at T _P 232, 360, 455 and 495°C. The kinetic parameters were obtained from analysis of the TG-DTG curves by Achar and Madhusudanan—Krishnan—Ninan (MKN) methods. The most probable mechanisms for the first stage was suggested by comparing the kinetics parameters.This revised version was published online in November 2005 with corrections to the Cover Date.     

4,4′-联喹啉酸铅(Ⅱ)配位聚合物(英文)

消旋轴手性配体(R,S)-4,4′-联二喹啉-3,3′-二甲酸乙酯(DBD)(1)与Pb(OAc)2在吡啶催化水热140℃合成条件下合成一新颖的配位聚合物[Pb(BD)(pyridine)]n(3),荧光测量表明,该配位聚合物与有机配体一样,在390nm附近展现紫色荧光。     

A Novel Method for Synthesizing 4,4′-Bis(hydroxymethyl)-2,2′-bipyridine

IntroductionSince C. W. Tang firstly reported theelectroluminescence of 8- hydroxyquinolinealuminium[1] ,much attention has been paid to themetal complexes as electro- luminescent materials.Based on a series of experimental data,it has beenknown that the electroluminescence of metalcomplexes with heterocyclic ligands containing Nand O elements mainly results from the tripletstatetransition.For some transitional metal complexes,there exist the transitions from metal to ligand( MLCT) at thei…     

Coordination Networks Self-assembled by Transition Metal Salts With 4,4′-oxydianiline (4,4′-oda). Syntheses and Structures of ∞ 1 [Ni(NCS) 2 (4,4′-oda) 2 ], ∞ 2 [Co(NCS) 2 (4,4′-oda) 2 ] and ∞ 2 [M(N 3 )(4,4′-oda) 2 ]NO 3 (M=Cd II or Co II )

Four infinite complexes X 1 [Ni(NCS) 2 (4,4'-oda) 2 ], X 2 [Co(NCS) 2 (4,4'-oda) 2 ] and X 2 [M(N 3 )(4,4'-oda) 2 ]NO 3 [M=Cd II ( 3 ) or Co II ( 4 )] were obtained by reactions 4,4'-oxydianiline (4,4'-oda) with Ni(SCN) 2 , Co(SCN) 2 , Cd(N 3 ) 2 and Co(N 3 ) 2 , respectively which have been structurally established by single-crystal X-ray diffraction. Complex 1 contains one-dimensional double-stranded chains comprising 24-membered Ni 2 (4,4'-oda) 2 macrocycles, each formed by two 4,4'-oda ligands and two octahedral Ni II centers. Complex 2 exhibits two-dimensional non-interpenetrating networks consisting of large 48-membered macrocycles each formed by four 4,4'-oda ligands and four octahedral Co II centers. The crystal structures of 3 and 4 are isomorphous and both contain one-dimensional double-stranded chains comprising 24-membered M 2 (4,4'-oda) 2 macrocycles, which are interlinked by w -1,3-azide groups to generate cationic two-dimensional sheets. These sheets are further connected by hydrogen bonds between the amine groups and nitrate ions to furnish three-dimensional networks. Crystal data: complex 1 crystallizes in the monoclinic space group P 2 1 / c with a =11.990(4) Å, b =9.413(4) Å, c =12.827(4) Å, g =116.32(2), V =1297.6(8) Å 3 and Z =2; complex 2 crystallizes in the orthorhombic space group Pbca with a =9.583(2) Å, b =12.738(3) Å, c =21.039(4) Å, V =2568.2(9) Å 3 and Z =4; complex 3 crystallizes in the monoclinic space group C 2/ c with a =23.036(5) Å, b =5.920(1) Å, c =17.800(4) Å, g = 92.67(3), V =2424.8(9) Å 3 and Z =4; complex 4 crystallizes in the monoclinic space group C 2/ c with a = 22.861(5) Å, b =5.812(1) Å, c =17.720(4) Å, g =93.00(3), V =2351.2(8) Å 3 and Z =4.     

Asymmetric Synthesis of (S)-Dimethyl-4,4′-dimethoxy-5,6,5′,6′-dimethenedioxybiphenyl-2,2′-dicarboxylate

Schizandra chinesis(wuweizi)has long been used in Chinese herbal medicine.Schisandrin C,as a constituent of Schizandra chinesis,shows various pharmacologicalactivities1.The similar compound,dimethyl-4,4′-dimethoxy-5,6,5′,6′-dimethenedi-oxy-biphenyl-2,2′-dicarboxylate(α-DDB),discovered by Xie2,3et al.in the investing-ation of schisandrin C,and some derivatives have also exhibited anti-HIV and anti-HBVactivity4.Further study of this kind of biphenyls has attracted considerable attenti…     

Photochemical Behavior of Platinum(II) and Palladium(II) Complexes of 4,4′-Dimethyl-2,2′-Bipyridine

Several mixed-ligand complexes of formula [MX 2 (MBPY)] {where M is Pd(II) or Pt(II); X is Cl m , I m , N 3 m or NO 2 m and MBPY is 4,4'-dimethyl-2,2'-bipyridine} have been prepared. The UV-Vis spectra of these complexes were found to show a low-lying MLCT band and on irradiation at the MLCT band these complexes sensitize the oxidation of 2,2,6,6-tetramethyl-4-piperidinol (XH) in N , N -dimethylformamide (DMF) to 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinoloxy free radical (XO). This photo-oxidation reaction involves singlet molecular oxygen ( 1 O 2 ) as an intermediate and its presence was confirmed by quenching studies using bis(diethyldithiocarbamato)nickel(II) [Ni(DDTC) 2 ], a well-known 1 O 2 quencher. The ability of the complexes to photosensitize the above photo-oxidation reaction follows the order: [Pt ( N 3 ) 2 ( MBPY ) ] ( 2 ) ～ [Pt ( NO 2 ) 2 ( MBPY ) ] ( 3 ) > [PtCl 2 ( MBPY ) ] ( 4 ) > [PtI 2 ( MBPY ) ] ( 1 ) > [Pd ( NO 2 ) 2 ( MBPY ) ] ( 7 ) ～ [Pd ( N 3 ) 2 ( MBPY ) ] ( 6 ) > [PdCl 2 ( MBPY ) ] ( 8 ) > [PdI 2 ( MBPY ) ] ( 5 ), which reflects the nature of the metal ion and the nature of the ligands present in the complexes.     

Synthesis and charge transfer interactions of cyclobis(4,4′-azopyridinium-p-phenylene)

A new tetracationic cyclophane, cyclobis(4,4′-azopyridinium-p-phenylene) (2.4PF₆), was synthesized via template-directed synthesis and characterized by MS and NMR spectroscopy. For the preparation of π-electron-deficient 2.4PF₆, the use of π-electron-rich templates such as 1,4-bis[2-(2-hydroxyethoxy)ethoxy]-benzene (4) and 1,5-bis[2-(2-hydroxyethoxy)ethoxy]naphthalene (5) enhanced the cyclophane formation in 17 and 19% yields, respectively. ¹H NMR spectra of the reaction mixture revealed that the cyclophane precursor 1.2PF₆ formed supramolecular assembling complexes with hydroquinone derivatives 4 and 5 before the ring formation. The intermolecular charge transfer interaction and the stability constants (K_a) of complexes generated between the electron-acceptor 2.4PF₆ and electron-donors 1,4-dimethoxybenzene 3, 4, and 5 were evaluated using UV-vis. spectroscopy and spectroscopic titration. The absorption bands attributable to CT interactions were centred at 580 nm for 3, 635 nm for 4, and 646 nm for 5, with stability constants of 17 ± 2, 2100 ± 200, and 2400 ± 300, respectively.     

Synthesis and crystal structure of cyclotris-(4,4′-thiodiphenylene ketone)

The side reaction of macrocyclization that occurs during the synthesis of poly-(1,4-phenylenesulfide ketone) by polycondensation of a 4,4-dihalobenzophenone with sodium sulfide was studied. It was found that the major product of this reaction is a cyclic trimer, cyclotris-(4,4"-thiodiphenylene ketone) (1). Despite the fact that ketone bridges are more rigid than sulfide bridges, the yield of the macrocycle is rather high, as it is in the synthesis of poly-(1,4-phenylenesulfide), and reaches 20% under high dilution conditions. The structure of 1 was investigated by X-ray diffraction analysis (R = 0.069 on 3138 reflections). Macrocycle 1 is strongly flattened in the crystal; the conformation observed is determined by the packing, since stereochemical analysis indicates high flexibility of the macrocycle. The solvate acetone molecules incorporated in the crystal are disordered, nevertheless, they are strongly fixed in the cavities and channels of the crystal structure.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1460–1466, August, 1994.     

Reactivity of the amino groups in 3,3′-diamino-4,4′-di(p-aminophenoxy)diphenylsuIfone

Reactivities of the amino groups in 3,3-diamino-4,4-di(p-aminophenoxy)diphenylsulfone were estimated by MO calculations using the Paryzer-Parr-Pople method, by potentiometric measurement of their pK _a values, and by the¹³C NMR spectroscopic study of the products obtained on reaction of the tetramine with two moles of 1,8-naphthalic anhydride. The results of these studies prove unambiguously the higher reactivity of the amino groups in positions 4 and 4 of the phenoxide moieties.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 296–299, February, 1993.     

4,4′-(多苯基三联苯)双(有机硅烷)的合成

前文曾经报道利用四苯基环戊二烯酮为双烯体,乙烯基或烯丙基三乙氧基硅烷及其硅氧烷为亲双烯体通过Diels-Alder反应合成的多苯基芳基有机硅化合物作为硅橡胶的热     

Tris(Trifluoroacetylacetonato)(4,4′-bipyridyl-N,N′-dioxido)Lanthanum(III)∶ A One-dimensional Polynuclear Complex

A novel one-dimensional polynuclear complex, tris(trifluoroacetylacetonato)(4,4'-bipyridyl- N , N '-dioxido)lathanum(III), was synthesized and characterized by elemental analysis and IR spectroscopy. X-ray structure analysis revealed that the complex has an infinite one-dimensional polynuclear structure with the 4,4'-bipyridyl- N , N '-dioxide as a bridge. La(III) is coordinated to eight oxygen atoms, six from three trifluoroacetylacetonate anions and two from two 4,4'-bipyridyl- N , N '-dioxide molecules to form a slightly distorted square antiprismatic coordination polyhedron. The coordination moiety was linked through 4,4'-bipyridyl- N , N '-dioxide forming a one-dimensional chain.