N-heterocyclic amine-directed structures and properties of two Cu(ii) diphosphonates
作者:Kui-Rong Ma、Feng Ma、Yu-Lan Zhu、Lin-Juan Yu、Xiao-Min Zhao、Yin Yang、Wei-He Duan
DOI:10.1039/c1dt10528k
日期:——
By introducing the second organic N-heterocyclic ligands 4′-(4-pyridyl)-4,2′:6′,4′′-terpyridine (pyterpy) and 4,4′-bipyridyl (4,4′-bipy), two examples of Cu(II)-diphosphonates, [Cu3(HL)2(Hpyterpy)2]·2H2O 1 and [Cu4(HL)2(4,4′-bipy)(H2O)5] 2 based on 1-hydroxyethylidenediphosphonic acid (H5L = CH3C(OH)(PO3H2)2), have been hydrothermally obtained and characterized by powder X-ray diffraction, elemental analysis, IR, TG-DSC. The single-crystal X-ray diffractions reveal that compound 1 has a one-dimensional fishbone-like chain constructed by anions [Cu3(HL)22−]n while simultaneously organic cations [Hpyterpy+]n suspending both sides, and compound 2 exhibits two-dimensional inorganic-organic alternate arrangement layer built from 1-D ladder-like inorganic chain with tetranuclear cluster [Cu4O10] via4,4′-bipy linkage. The results of electrochemical measurements indicate half-wave potential of 1 (E1/21 = 1.01 V) is less than that of 2 (E1/22 = 1.20 V), indicating a good D-A system in ICT for 1. Moreover fluorescent measurements reveal that emission intensity of 1 centered at 422 nm is larger than that of 2 emitted at 420 nm, caused by intraligand π*–π emission state of organic N-heterocyclic amine (λex = 233 nm). Magnetism data indicate that compound 1 exhibits ferrimagnetic interactions between metal centers, while compound 2 has antiferromagnetic property.
通过引入第二种有机N-杂环配体4′-(4-吡啶基)-4,2′:6′,4′′-三吡啶(pyterpy)和4,4′-联吡啶(4,4′-bipy),基于1-羟乙叉二膦酸(H5L = CH3C(OH)(PO3H2)2)的两种铜(II)双膦酸盐[Cu3(HL)2(Hpyterpy)2]·2H2O(1)和[Cu4(HL)2(4,4′-bipy)(H2O)5](2)已通过水热法获得,并通过粉末X射线衍射、元素分析、红外光谱、热重-差示扫描量热法进行表征。单晶X射线衍射结果显示,化合物1具有一维鱼骨状链结构,由阴离子[Cu3(HL)22−]n构成,同时有机阳离子[Hpyterpy+]n悬浮在两侧;而化合物2则表现出二维无机-有机交替排列的层状结构,由一维梯状无机链与四核团簇[Cu4O10]通过4,4′-bipy联结而成。电化学测量结果表明,化合物1的半波电位(E1/21 = 1.01 V)小于化合物2(E1/22 = 1.20 V),表明1在内部电荷转移(ICT)方面具有良好的供体-受体体系。此外,荧光测量显示,化合物1在422 nm处的发射强度大于化合物2在420 nm处的发射强度,这是由有机N-杂环胺的配体内π*–π发射态引起的(λex = 233 nm)。磁性数据表明,化合物1表现出金属中心之间的铁磁相互作用,而化合物2则具有反铁磁特性。