Combination chemistry of hexa-copper-substituted polyoxometalates driven by the Cu(II)-polyhedra distortion: from tetramer, 1D chain to 3D framework.
Reaction of CuCl(2) x 2 H(2)O and trivacant Keggin polyoxoanion Na(9)[A-alpha-PW(9)O(34)] x 7 H(2)O in the presence of ethylene-diamine/1,2-diaminopropane (en/enMe) under hydrothermal conditions led to five novel inorganic-organic hybrid polyoxotungstates (POTs):[Cu(en)(2)](2)[Cu(en)(2)(H(2)O)](2)[Cu(H(2)O)(2)][Cu(4)(H(2)O)(2)(B-alpha-PW(9)O(34))(2)] x 2 H(2)O(1), [Cu(6)(mu(3)-OH)(3)(en)(3)(H(2)O)(5)(B-alpha-PW(9)O(34))] x 6 H(2)O (2), Na(6){[Cu(6)(mu(3)-OH)(3)(en)(3)(H(2)O)(2)(B-alpha-PW(9)O(34))](2)[Cu(4)(H(2)O)(2)(B-alpha-PW(9)O(34))(2)]} x 2 H(2)en x 8 H(2)O (3), [Cu(6)(mu(3)-OH)(3)(en)(3)(H(2)O)(3)(B-alpha-PW(9)O(34))] x 4 H(2)O (4), [Cu(II)(6)Cu(I)(4)(mu(6)-O)(OH)(18)][Cu(6)(mu(3)-OH)(3)(enMe)(3)(H(2)O)(3)(B-alpha-PW(9)O(34))](4) x 4 H(3)O x 2 H(2)O (5). 1 is a new 1D chain constructed from alternate tetra-Cu(II) sandwiched units [Cu(II)(4)(H(2)O)(2)(B-alpha-PW(9)O(34))(2)](10-) and dinuclear [Cu(II)(2)(H(2)O)(6)](4+) units. 2-5 are a series of novel transition-metal substituted polyoxometalates (TMSPs) comprising hexa-Cu(II) substituted {Cu(6)PW(9)} units (Cu(6) = Cu(6)(mu(3)-OH)(3), PW(9) = B-alpha-PW(9)O(34), Scheme 1). 2 is an unusual monomer. 3 is an unprecedented tetramer built by two types of TMSP units, [Cu(6)PW(9)(en)(3)(H(2)O)(2)] and [Cu(II)(4)(H(2)O)(2)(PW(9))(2)](10-). 4 is a novel chain assembled from [Cu(6)PW(9)(en)(3)(H(2)O)(3)] units by double-bridging mode. Most interestingly, 5 is a open framework made by [Cu(6)PW(9)(enMe)(3)(H(2)O)(3)] units, in which the novel decacopper oxygen clusters, [Cu(I)(4)Cu(II)(6)(mu(6)-O)(OH)(18)](4-) formed in situ, are encapsulated into the channels, and 5 represents the first decametallic-cluster-containing open framework built by TMSP units. 2-5 all contain the hexa-Cu(II) substituted POT unit {Cu(6)PW(9)L(3)(H(2)O)(n)} (L = en/enMe, n < 6) made by {Cu(6)L(3)(H(2)O)(n)} core and trivacant Keggin PW(9) fragments. Moreover, 3-5 can be viewed as combining derivatives of 2 through substituting water ligands on hexa-Cu(II) {Cu(6)L(3)(H(2)O)(n)} units by terminal oxygen atoms of PW(9) units. Importantly, the Cu(II)-polyhedra Jahn-Tell/pseudo-Jahn-Teller distortion plays a crucial role in the formation of 1-5. The magnetic behaviors of 2-5 show antiferromagnetic interactions between the Cu(II) ions in the hexa-Cu(II) cluster.
Li
Bing
B
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China.
Zhao
Jun-Wei
JW
Zheng
Shou-Tian
ST
Yang
Guo-Yu
GY