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四氮唑-1-乙酸配合物的合成、晶体结构、谱学表征及磁性质研究

Studies on the Synthesis, Crystal Structures, Spectroscopic Characterization and Magnetic Properties of Complexes of Tetrazole-1-acetic Acid

【作者】 张秀清

【导师】 梁宏; 于青;

【作者基本信息】 广西师范大学 , 无机化学, 2006, 硕士

【摘要】 利用溶液法,本文合成了十四个尚未见报道的配位聚合物。通过红外光谱、元素分析、X-射线单晶衍射等手段,较系统地研究了它们的晶体的结构,并测定了配合物(1)4的磁性质和配合物(7)、(8)的固体荧光性质。所用的配体四氮唑-1-乙酸(Htza)在本论文中出现了以下几种配位方式:本论文分为以下三部分:第一章:通过调控反应体系的pH值或加入第二配体的方法,合成了五种四氮唑-1-乙酸铜的配合物{[Cu(tza)2(Htza)2]·2H2O}n (1), [Cu(tza)2]n (2), {[Cu2(tza)2(CH3COO)(μ3-OH) (H2O)]·H2O}n (3), [Cu2(tza)3(μ3-OH)·2H2O]n (4), {[Cu(tza)(phen)](ClO4)}n (5).合成配合物(1)时,反应体系的pH值为2.02.5,配合物中配体以(b)和(c)两种形式存在,Cu(II)通过(c)连接成一维链状结构,相邻的链间通过氢键组装成二维网状超分子配合物。合成配合物(2)时,反应体系的pH值为3.0,配合物中配体均以(d)的形式存在,将Cu(II)连接成二维网状配位聚合物。合成配合物(3)时的pH值为3.87,配合物的每一个单元中有两个μ3-OH将四个Cu(II)连接在一起,然后通过(d)和(i)两种配位形式连接成二维网状结构,又由氢键组装成三维超分子配合物。合成配合物(4)时的pH值为5.5,配合物(4)和配合物(3)的结构单元一样,但配合物(3)中还有CH3COO-与铜配位,并且在二者中配体的配位形式不同。配合物(4)中Cu(II)通过(c)、(d)、(e)的形式连接成二维网状结构,然后通过氢键连接成三维超分子配合物。在配合物(5)中,加入了第二配体phen以考查其对配合物结构的影响。由于phen与Cu(II)配位,增加了空间位阻,Cu(II)只是通过(e)的形式连接成一维无限z形链结构。配合物(1)、(2)、(4)、(5)属单斜晶系,空间群分别为C2/c、P2(1)/c、P2(1)/n、C2/c;配合物(3)属三斜晶系,空间群为P-1。第二章:本章用四氮唑-1-乙酸和Zn(II)、Cd(II)、Pb(II)的氧化物及Cd(II)、Co(II)的高氯酸盐反应,合成了五种配合物[Zn2(tza)3(μ3-OH)(H2O)·2H2O]n (6), [Cd(tza)2]n (7), {[Cd(tza)(2,2?-bipy)(H2O)](ClO4)}n (8), {[Co(tza)(2,2?-bipy)(H2O)](ClO4)}n (9), [Pb(tz- a)2]n (10).主要考查了第二配体、不同的金属离子对配合物配位构型的影响。配合物(6)中,配体以(c)、(e)、(h)的形式存在,将金属离子Zn(II)连接成二维网状配位聚合物。配合物(7)中,配体以(e)的形式存在,将金属离子Cd(II)连接成三维网络配位聚合物。在合成配合物(8)时,加入了2,2?-bipy,配合物中Cd(II)通过(e)沿bc面连接成二维网状结构。由于2,2?-bipy的参与,使配合物(8)在a轴方向的伸展受到限制,但面与面间仍通过氢键和π-π堆积作用组装成三维超分子网络结构。配合物(9)中金属离子Co(II)配位构型以及空间排列方式和配合物(8)中的Cd(II)完全一致,只是相应的键长稍有变化。在配合物(10)中,配体以(f)的形式与Pb(II)配位,形成一维链状结构。在链状结构中,Pb(II)有两种取向,链间相邻的Pb(II)之间存在弱的Pb-O···Pb键,通过这种弱的相互作用,配合物(10)在空间形成三维网络超分子聚合物。配合物(6)为三斜晶系,空间群为P-1;配合物(7)10均属单斜晶系,空间群分别为P2(1)/n、P2(1)/c、P2(1)/c、C2/c。第三章:本章用四氮唑-1-乙酸和稀土氧化物合成了四种配合物,[La(tza)3(H2O)2·2H2O]n (11), [Pr(tza)3(H2O)2·2H2O]n (12), [Nd(tza)3(H2O)2·1.5H2O]n (13), [Sm2(tza)6(H2- O)5·H2O]n (14).配合物(11)和(12)中金属离子的配位构型以及空间排列方式完全一样,金属离子通过(c)和(g)的形式连接成一维链状结构,然后通过氢键组合成三维超分子配合物。而配合物(13)中Nd(III)的配位构型没变,但配体在金属离子周围的排列发生了变化。配合物(14)与前三个配合物的差别较大,每一结构单元中出现了Sm(III)1和Sm(III)2两种不同配位构型的中心金属离子。Sm(III)1的配位构型和配合物(13)中Nd(III)的完全一样,Sm(III)2则是八配位以双核单元的形式存在,每个单元通过分子间氢键连接成二维网状结构。Sm(III)1的链和Sm(III)2的网又通过氢键形成三维超分子结构。配合物(11)和(12)属单斜晶系,空间群均为P2(1)/c;配合物(13)和(14)属三斜晶系,空间群均为P-1。在2320 K温度范围内测定了配合物(1)4的变温磁化率。磁性数据表明:配合物(1)的金属离子间表现为反铁磁相互作用,配合物(2)的金属离子间表现为铁磁相互作用,配合物(3)和(4)的金属离子间均存在净的反铁磁相互作用。在相同条件下测了配合物(7)和(8)的固体荧光(室温)。配合物(7)没有荧光发射;配合物(8)在波长λem = 445 nm (λex = 397 nm)处有最大荧光发射,属于LLCT跃迁。

【Abstract】 In this dissertation, fourteen new coordination complexes have been synthesized by the liquid method. They were studied by IR, Elemental Analysis and single crystal X-ray diffraction methods. The magnetic properties of polymers (1) to (4) and the fluorescence spectra data of polymers (7) and (8) are measured.The ligand we used is tetrazole-1-acetic acid (Htza), and it has several coordination modes in this dissertation, as follows:There are three chapters in this dissertation:Chapter one: Five new complexes of Htza with Cu(II) are synthesized by controlling the pH value of the reaction system or adding the second ligand. They are {[Cu(tza)2(Htza)2]·2H2O}n (1), [Cu(tza)2]n (2), {[Cu2(tza)2(CH3COO)(μ3-OH)(H2O)]·H2O}n (3), [Cu2(tza)3(μ3-OH) 2H2O]n (4), {[Cu(tza)(phen)](ClO4)}n (5). The pH value of the reaction system from (1) to (4) is 2.02.5, 3.0, 3.87, 5.5, respectively. The ligands coordinate with Cu(II) ions via (b) and (c) in complex (1), and the Cu(II) ions are connected to 1-D chain structure. Then, the neighboring chains are assembled to 2-D network structure by hydrogen bonds. In complex (2), the ligands coordinate with Cu(II) ions by (d), and the Cu(II) ions are linked into 2-D network structure. There are twoμ3-OH in one structural cell of complex (3), and four Cu(II) ions are connected by them. Then, the structural cells are linked into 2-D network structure by (d) and (i), and the 2-D network structure is assembled to 3-D meshwork structure via hydrogen bonds. The structure of complex (4) is similar to complex (3). But, there is CH3COO- in complex (3). And the Cu(II) ions of complex (4) are connected to 2-D network structure by (c), (d) and (e).In complex (5), the phen is added in order to study the influence of the second ligand on the complex structure. The spacial resistance is enhanced because the phen coordinates with Cu(II). So the Cu(II) ions of complex (5) are only linked into 1-D z chain structure via (e). Complex (1), (2), (4), (5) belong to monoclinic system, space groups are C2/c, P2(1)/c, P2(1)/n, C2/c, respectively. Complex (3) belongs to Triclinic, space group P-1. Chapter two: Five new polymers are synthesized by reaction of Htza with oxides of Zn, Cd, Pb and perchlorides of Cd, Co in this part. They are [Zn2(tza)3(μ3-OH)(H2O)·2H2O]n (6), [Cd(tza)2]n (7), {[Cd(tza)(2,2?-bipy)(H2O)](ClO4)}n (8), {[Co(tza)(2,2?-bipy)(H2- O)](ClO4)}n (9), [Pb(tza)2]n (10). We study the influence of the second ligand and different metallic ions on the complex structure. In complex (6), the Zn(II) ions are connected to 2-D network structure by (c), (e) and (h). But in complex (7), the ligands link Cd(II) ions into 3-D meshwork structure polymer only via (e). In complex (8), 2,2?-bipy is added and the Cd(II) ions are connected to 2-D network structure by (e). The extension of complex (8) along a axis is limited because the 2,2?-bipy coordinates with Cd(II) ions . But the neighboring planes are assembled into 3-D meshwork supermolecular structure via hydrogen bonds andπ-πstacking. The configuration of Co(II) ions in complex (9) is the same as Cd(II) ions in complex (8). But the corresponding bond length varies a little. In complex (10), the ligands link Pb(II) ions into 1-D chain structure by (f). The Pb(II) ions have two tropism in one chain, and the neighboring Pb(II) ions have Pb-O···Pb weak interaction in adajacent chains. The complex (10) is assembled into 3-D meshwork supermolecular structure by that weak interaction.Complex (6) belongs to Triclinic system, space group P-1. Complex (7) to (10) belong to monoclinic system, and space groups are P2(1)/n、P2(1)/c、P2(1)/c、C2/c, respectively.Chapter three: Four new rare earth polymers are synthesized by reaction of Htza with oxides of rare earth. They are [La(tza)3(H2O)2·2H2O]n (11), [Pr(tza)3(H2O)2·2H2O]n (12), [Nd (tza)3(H2O)2·1.5H2O]n (13), [Sm2(tza)6(H2O)5·H2O]n (14). The configuration of metal ions are the same in complex (11) and (12), and the metal ions are connected to 1-D chain structure via (c) and (g). Then, the chains are assembled into 3-D meshwork supermolecular structure by hydrogen bonds. In complex (13), the configuration of Nd(III) ions is the same as complex (11) and (12), but the arrangement of ligands is changed. There are two kinds of Sm(III) ions in complex (14). The configuration of Sm(III)1 ions is the same as Nd(III) ions in complex (13), but the Sm(III)2 ions are eight-coordinated and they are dinuclear cells. Adjacent dinuclear cells are linked into 2-D network structure by intermolecular hydrogen bonds. Then, the chains of Sm(III)1 and the 2-D network structure of Sm(III)2 are assembled into 3-D meshwork supermolecular structure.Complex (11) and (12) belong to monoclinic system, space groups are all P2(1)/c; Complex (13) and (14) belong to Triclinic system, space groups are all P-1.Variable-temperature magnetic susceptibility of complexes (1) to (4) were performed in the 2320 K region by using powder samples. The antiferromagnetic interaction among the metal ions are evident from the susceptibility data in complex (1) and ferromagnetic interaction in complex (2); And the pure antiferromagnetic interactions are showed in complex (3) and (4).At room temperature, the fluorescence of complex (7) and (8) are measured in the solid state on the same condition. There is no fluorescence emission in complex (7). While complex (8) shows the fluorescence emission withλem = 445 nm (λex = 397 nm). The emission observed in complex (8) is tentatively assigned to the ligands fluorescence(LLCT).

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