第37卷第10期 湖州师范学院学报 Vol|37 No.1O 2015年1O月 Journal of Huzhou University 0ct。2015 Synthesis and Structural Characterizati0n of Zinc Complex Zn(Him)2(bna)2 Constructed by 5一Bromonicotinic Acid LI Zhenyang,HE Yige,FU Qianyun,WANG Liqiong,NI Shengliang (School of Life Science,Huzhou University,Huzhou 313000,China) Abstract:A novel zinc complex Zn(Him)2(bna)z1(Him=imidazole,Hbna=5一bromonicotinic acid)has been hy— drothermally synthesized and characterized by powder XRD.FT—IR.TG—DTA and single crystal X—ray diffrac tion.Colorless crystals crystallize in the triclinic system,space group P一1 withⅡ一9.273(2)A,b=10.971(2)A, c l1.162(2)A,口一97.4(1)。, =105.1(1)。,7=100.0(1)。,V:1 061.4(4)A。,C18 H】4 Br2 N6() Zn,Mr一 603.54,Dc一1.888 g・cm_‘, (MoKa)一4.960 mm一,F(000)一592,Z一2,the finalRl—O.048 3 and wR z一 0.1O6 1 for 2 403 observed reflections with(I>2a(,)).The zinc(II)atom structure in 1 exhibits a slightly dis— torted tetrahedron geometry,the self—assemble molecules form a chain along the b crystallographic direction con— nected by N—H…0 hydrogen bonds.Furthermore,the fluorescence property of the complex 1 has also been inves— tigated.CCDC 1024450. Key words:zinc(II)complex;5一bromonicotinic acid;structural characterization;hydrothermal synthesis (:LC number:O614.121 Document code:A Article ID:1009一】734(20]5)10—0027—05 The metallosupramolecular chemistry has become an exciting research field in recent years owing to the generation of materials with various intriguing structural topologies and their potential applications in the areas of catalysis,gas storage,separation,magnetism,and luminescence[ ~ .Recently,5一bro— monicotinato ligands have been actively utilized as construction units to obtain many supramolecular complexes.For example,Gul_3_and c0一workers investigated the assembling supramolecular networks by halogen bonding in coordination polymers driven by 5一bromonicotinic acid.LiL studied solid—state conversions of Cd(II)coordination frameworks with 5~bromonicotinate,Cheng[ ]reported Co(II)coor— dination polymers with 5一bromonicotinate induced by different synthetic approaches and SenL j have synthesized three dimeric lanthanide carboxylate complexes which were heterogeneous catalyst in olefin epoxidation reactions. Hence,in this work by employ 5一bromonicotinate as the main ligand source and introducing a N— donor imidazole ligand,we further report the synthesis and structure of Zn(Him)2(bna)21 in detail. 1 Experimental 1.1 Materials and instruments All chemicals were of reagent grade and used without purification.The infrared spectra were taken on a * Received date:2O15—06—28 Foundation items:This research is supported by the Education Department Proiect of Zhejiang Province(FX20131 36). Biography:NI Shengliang,Associate Professor,Research Interest:Syntheses and crystal structure of organic—met al complexes.E—mail:nisl@hutc.zj.cn 28 湖州师范学院学报 第37卷 Nicolet FT—IR 5 700 spectrometer in the range of 4 000 ̄400 cm。。。by KBr pellet technique.Combined TG/ DTA measurements were carried out in range room temperature ̄900℃using powdered samples in a nitrogen stream on a Seiko Exstar 6 000 TG/DTA 6 300 system with a heating rate of 10℃/min.Powder X—ray dif— fraction measurements were carried out with a Bruker D8 Focus X—ray diffractometer to check phase purity.Fluorescence spectra for crystal solid state samples were recorded at room temperature on Hita— chi F一4 600 fluorescence spactraphotometer.Single crystal X~ray diffraction data were collected by a Rigaku R—Axis Rapid X—ray diffractometer. 1.2 Synthesis Dropwise addition of 1.4 cm。(1.0 M)Na2CO3 to a stirred aqueous solation of ZnSO4・7H2O(O.399 0 g, 1.4 mmo1)in 9 cm。of H2 O produced a white precipitate,ZnCO3・y H2 O,which was separated by centrifu— gation and washed with doubly destilled water until no S0;一anions were detectable.The white precipitate was added to a mixed solution of 5 bromonicotinic acid(O.565 7 g,2.8 mmo1)and imidazole(0.190 7 g,2.8 mmo1) in 21 cm。CH3OH/H2O(2:1,V/V).The mixture was stirred for 30 minutes,subsequently,was trans— ferred into 25 cm。Teflon liner,which was sealed in a stainless autocave.The reaction was carried out at 120℃for 24 h under autogeneous pressure.After the autoclave was cooled to room temperature,the re— suiting colorless solution was allowed to stand at room temperature for 1 week,colorless block crystals for complex 1 were obtained by slow evaporation in a yield of 42 based on ZnSO4・7 H2 O.Compared with crystal simulated powder XRD data,the powder XRD spectrum of the complex 1 showed high pure crystal— line phases.IR(KBr disc,cm ):3 125(w),2 878(w),1 614(s),1 553(m),1 381(s),1 066(m),743(m). 1-3 Crystal structure determination A colorless block single crystal with dimensions of 0.76 mm×0.49 mm×0.42 mm for complex 1 was fixed with epoxy cement on respective fine glass fiber。which were then mounted on a Rigaku R— Axis Rapid X—ray diffractometer with graphite—monochromated Mo K radiation( 一0.710 73A)u— sing the∞scan mode(3.10≤0≤25.00。)at 293 K.A tota1 of 8 450 reflection were collected and 3 733 were independent(Ri 一0.084 2),of which 2 403 were observed with I>2o-( ).The structure was solved by direct methods using SHEI XS一97 program[ ]and refined with SHELXL一97[。]by full—ma— trix least—squares technique on F .All non—hydrogen atoms were located geometrically and refined isotropieally.The final R1=0.048 3,wR 2—0.106 1(叫一1/[d (F:)十(o.040 8P) +2.253 6P]),where P===(F +2 F )/3,S一1.132,(△/o)一O.01,(△-D) 。 一0.812,(△,9) i 一一1.223 e・A_。.Selected bond and hydrogen bond lengths and angles are given in Table 1. Table 1 Bond Selected Bond and Hydrogen Bond Lengths( )and Bond Angles(。)for 1 Dist. Bond Dist. Bond Dist. Zn—O(1) Zn—O(3) 1.967(5) 1.983(5) Zn—N(3) Zn—N(5) 2.005(6) 2.005(6) Br(1)一C(4) Br(2)一C(11) 1.892(8) 1.891(7) Angle O(1)一Zn—O(3) O(1)一Zn—N(3) (。) 98.6(2) 106.6(2) Angle O(1)一Zn—N(5) 0(3)一Zn—N(3) (。) l2O.3(2) 107.0(2) Angle O(3)一Zn—N(5) N(5)一Zn—N(3) (。) 11 7.4(2) 106.0(3) Hydrogen bonding contact Symmetry codes:Ⅱ一一z+1,一y+2,一 +1;b一一z+1,一Y+1,一z+1 第10期 U 删'et al:Syng ̄sandSm曲 Q盯act ∞d (]c H (br如Q幅 5一 ∞瑚 id 29 2 Results and Discussions 2.1 Structure description The compound Zn(Him)2(bna)21 crystallizes in the triclinic space group P一1.The asymmetric unit of 1 c0ntains one Zn(II)atom,two imidazole molecules and two distinct 5一bromonicotinato ligands.As shown in Fig.1,the four—coordinate Zn(II)center surrounded by two carboxylate O atoms from 5一bromonicotinate and two N atoms from imidazole molecules,which completed a distorted tetrahedron geometry. The 5一bromonicotinate moieties adopt monodentate coordination mode.The Zn—N bond lengths are the same as the va1ue of 2.005(6)A,the Zn—O lengths and O(N)一Zn一0(N)angles are range from 1.967(5)to 1.983(5)A and 98.6(2)。to 120.3(2)。,respectively,all of which are within the range ob— served for other four—coordinate Zn(II)complexes with oxygen and nitrogen donor ligands 。~ U。.Select— ed bond lengths and bond angles are given in Table 1. In the crvstal,the seif—asseruble molecules form a chain along the 6 crystallographic direction con— nected bv N—H…0 hydrogen bonds(N(6)一H(6A)…O(4)。一168。,N(6)…0(4)“一2.731(2)A,N(4) 一H(4A)…o(2) 一168。and N(4)…O(2) 一2.751(2)A)(口一一 +1,一Y+2,一2+1;b:=:一 +1, v+1,一z+1),as shown in Fig.2.These chains are further constructed layer parallel to the ab crys— 一ta11ographic plane by aryl ring丌一了c packing interactions between the adjacent pyridyl rings of 5一bro— monicotinate ligands leading to two—dimensional framework,in which the distances between two paral— lel pyridy1 rings are 3.789(4)A and 3.869(5)A.And the supermolecular layers are self—assemble to form three—dimensional network structure by van der waals interactions. Fig.1 The Ortep view of complex 1 with thermal ellipsoids at 45%probability(Partial H atoms were omitted for clarity) 2.2 IR spectrum and thermal stability Fig.2 View ofthe 1一Dchain structure or fcomplex 1 along b direction IR spectrum of the complex indicated that have four absorption between 3 125 cm一 and 2 878 bond stretching vibration of pyr cm一,which could be assigned to the asymmetric and symmetric C—H idy1 ring.Two strong,sharp bands at 1 6 1 4 cm一 and 1 38 1 cm一 could be attributed to asymmetric and symmetric—COO stretching vibration,respectively.The A7 Va1ue[y as(c==:O)一y s(c一0)]of 233 cm-1 suggest monodentate carboxylate group[11],also in agreement with the crystal structure.Demon— strate the TG—DTA curves(Fig.3)for the complex Zn(Him)2(bna)2 over the temperature range 25~ 900℃in flowing air atmosphere.The DTA curve of the title complex display two peaks centered at 205℃ and 375℃,respectively.At 205℃,the weight loss over 190~321℃reaches 22.55%corresponding we11 to 22.56%for liberation of 2 moL of imidazole molecules per formula unit,and the residue of 19・ 28%at 900℃might be a mixture of ZnO(calc.13.42 )and carbon black(3C,calc.5.96 )burning for 5一bromonicotinate ligand. 3O 2.3 Fluorescence property 湖州师范学院学报 第37卷 The fluorescence property of the complex 1 was investigated at room temperature in solid state,as shown in Fig.4.It can be observed that 1 displays blue photoluminescence with intense maximum emis— sion located at 429 nm upon excitation at 350 nm.Compared with the free ligand Hnba with maximum e— mission located at 41 1 nm,the difference should be attributed to the coordination of ligands to Zn(II). The significant red—shift phenomenon of the fluorescence emission of 1 here could be tentatively as— signed to the ligand—to—metal charge transfer(LMCT)[ . 三 . 3 普 凸 Temperature(℃) 一. .时一^.=∞口 =lII Fig.4 Solid—state emission spectrum of1 andfreeHnbawith^。 =350nm Fig.3 TG/DTA curvesfor the complex Zn(Him)2(bna)2 3 Conclusion In summary,a new supramolecular zinc complex,Zn(Him)2(bna)2,based on the Hnba ligand has been hydrothermally synthesized and its structure was characterized by FT—IR,TG—DTA and espe— cially single—crystal X—ray diffraction.The zinc(II)atom structure of the complex exhibits a slightly distorted tetrahedron geometry,and the compound is stabilized by intramolecular N—H…O hydrogen bonding interactions and aryl ring兀一7【packing interactions.The complex exhibit weak blue photolumi— nescrence in the solid state at room temperature.It is anticipated that more and more complexes contai— ning Hnba ligand will be synthesized with novel structures and properties. 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[11] Nakmoto K.Infrared and Raman Spectra of Inorganic and Coordination Compounds[M].Translated by Huang Deru, Wang Renqing.Beijing:Chemieal Industry Press,1986. Liu G X,Wang M L,Su L J,et a1.Syntheses,crystal structures and fluorescent properties of zinc coordination polymers [12] based O13_camphor acid and imidazole ligandEJ].Chinese J Inorg Chem,2011,27(6):1 185—1 190. 5一溴烟酸锌配合物Zn(Him) (bna) 的合成及其结构表征 李振阳,何一舸,傅倩云,汪丽琼,倪生良 (湖州师范学院生命科学院,浙江湖州313000) 摘 要:采用水热法合成了一个结构新颖的锌配合物Zn(Him) (bna) 1(Him一咪唑;Hnba一5一溴烟 酸),并用x射线粉末衍射、红外光谱、热重分析及x射线单晶衍射进行了结构表征.研究结果表明,配合物属 于三斜晶系,空间群P一1,晶胞参数为:n一9.273(2)A,b一10.971(2)A,C—l1.162(2)A,口一97.4(1)。, 一105.1(1)。,y一100.0(1)。,V:1 061.4(4)A。,Cl8H14 Br2N6O4Zn,Mr一603.54,Dc一1.888 g・cm~, 一 4.960 mm1。,F(000)一592,Z一2,最终偏离因子[j>2 (f)]R1—0.048 3,wR 2一O.106 1;在配位物晶体 中,中心锌离子形成了畸变的四面体配位模式,分子间通过N—H…O氢键作用沿b方向形成了一维超分子 链.并对配合物1的荧光性质进行了测试.cCDC1024450. 关键词:锌配合物;5一溴烟酸;结构表征;水热合成 [责任编辑高俊娥]