若干具有[(PO_4)_4Mo_6~ⅤO_(15)]^(12-)簇骼的化合物的光谱研究

Spectroscopic Studies of Compounds with [(PO_4)_4Mo_(6O)~Ⅴ_ 15] (12-) Cluster

用FTIR ,NIRFT Raman ,UV VisDRS和荧光光谱等对五个新型具有 [(PO4) 4 MoⅤ6O15]12 -阴离子簇的化合物 :Na·(H4TETA) 3 ·(H3 O) 5·{Zn[(HPO4) 2 (PO4) 2 Mo6O15]2 } (2 ) ,(H2 en) 7·(H3 O) 4 ·{Cu[(HPO4) 2(PO4) 2 Mo6O15]2 }·H2 O (3) ,(H3 DETA) 2 ·(H3 O) 3 ·{Co0 5[(HPO4) 2 (PO4) 2 Mo6O15]}·H2 O (4) ,[Co(H3 TETA) ]2 {Co0 5[(HPO4) (PO4) 3 Mo6O15]}· 3 5H2 O (5 )和 (H3 DETA)· (H3 O ) 4 · {Co1 5[(HPO4) 2(PO4) 2 Mo6O15]}·0 5H2 O (6 ) ,进行研究 ,并探讨其结构和性能的关系。这些化合物具有 {M [(PO4) 4 Mo6O15]2 }二聚体单元 ,化合物 2～ 4的二聚体间通过与有机分子和水分子的氢键形成三维网状结构 ;化合物 5和 6的 {Co[(PO4) 4 Mo6O15]2 }二聚体间是分别通过 [CoH3 TEATA]基团和CoO4四面体组成网状结构。磷钼酸盐的特征振动频率和这些化合物的结构相关 ;化合物的三个UV VisDRS特征谱带分别属于Od→Mo,Oμ→Mo和O→M电荷转移 ;观察到以 2 4 0nm激发 ,在 4 10nm附近出现的由Oμ→Mo跃迁激发引起的较强的荧光发射谱带。

Five novel organic-molybdenum phosphates with [(PO 4) 4MoⅤ 6O 15] 12- cluster, Na·(H 4TETA) 3·(H 3O) 5·{Zn[(HPO 4) 2(PO 4) 2Mo 6O 15] 2} (2), (H 2en) 7·(H 3O) 4·{Cu[(HPO 4) 2(PO 4) 2 Mo 6O 15] 2}·H 2O (3), (H 3DETA) 2·(H 3O) 3·{Co 0.5[(HPO 4) 2(PO 4) 2Mo 6O 15]}·H 2O (4), [Co(H 3TETA)] 2{Co 0.5[(HPO 4)(PO 4) 3Mo 6O 15]}·3.5H 2O (5) and (H 3DETA)·(H 3O) 4·{Co 1.5[(HPO 4) 2(PO 4) 2Mo 6O 15]}·0.5H 2O (6), have been synthesized. The relationship between their properties and structures was studied by using FTIR, NIR FT-Raman, UV-Vis DRS and fluorescence etc. In these compounds, every two [(PO 4) 4Mo 6 O 15] clusters are coordinated by a metal atom to form a {M[(PO 4) 4Mo 6 O 15] 2} dimer. In compound 2, 3 and 4, {M[(PO 4) 4Mo 6 O 15] 2} dimers are hydrogenbonded by the organic molecules and water molecules to form a three-dimensional expended framework, respectively. In compound 5 and 6, {Co[(PO 4) 4Mo 6 O 15] 2} dimers are coordinated by [Co(H 3TETA)] groups and tetrahedra to form a network, respectively. These characteristic vibrational frequencies of the molybdenum phosphates are related to the structure of these compounds. Three characteristic bands in UV-Vis DRS spectra of these compounds have to be attributed to the absorptions of O d→Mo, O μ→Mo and O→M charge transfer, respectively. These compounds exhibit strong fluorescence emission bands at about 410 nm when excited by 240 nm, which are caused by O μ→Mo charge transfer.