Investigation of Flexible Organic Ligands in the Molybdate System: Delicate Influence of a Peripheral Cluster Environment on the Isopolymolybdate Frameworks

Abstract

By introducing the flexible 1,4-bis(1,2,4-triazol-1-ylmethyl)benzene (L(1)) and 1,4-bis(imidazole-1-ylmethyl)benzene (L(2)) ligands into the molybdate system under hydrothermal conditions, 12 novel isopolymolybdate frameworks were obtained: [CuL(1)(H(2)O)][Mo(3)O(10)] (1), [ML(1)(H(2)O)(2)][Mo(3)O(10)] [M = Cu (2), Zn (3), and Co (4)], [Cu(2)(L(1))(4)][theta-Mo(8)O(26)] (5), [Cu(4)(L(1))(4)][beta-Mo(8)O(26)](0.5)[gamma-Mo(8)O(26)](0.5).H(2)O (6), [Ag(4)(L(1))(2)][beta-Mo(8)O(26)] (7), [M(2)(L(1))(3)(H(2)O)(4)][beta-Mo(8)O(26)].2H(2)O [M = Zn (8), Co (9), and Ni (10)], and [M(4)(L(2))(4)][delta-Mo(8)O(26)] [M = Cu (11) and Ag (12)]. Compound 1 and isostructural compounds 2-4 exhibit similar three-dimensional (3D) pillar-layered structures. Compound 5 shows a novel pillar-layered framework constructed from two sorts of [CuL(1)](n) left- and right-handed helical chains and the theta-[Mo(8)O(26)](4-) polyoxoanion. Compound 6 contains two sorts of isomers of beta-[Mo(8)O(26)](4-) and gamma-[Mo(8)O(26)](4-) coexisting in one structure, which induce the formation of two sorts of ladderlike building blocks and finally the polythread structure. The cationic and anionic fragments in compound 7, the dinuclear molecular loop of [Ag(2)(L(1))(2)](2+) and beta-[Mo(8)O(26)](4-), are both linked up by single Ag ions, forming two kinds of infinite chains of [Ag(3)(L(1))(2)](n)(3n+) and [Ag-beta-Mo(8)O(26)](n)(3n-), respectively. Compounds 8-10 are isostructural and exhibit the parallel two-fold (2D-->2D) interpenetrated networks based on the beta-[Mo(8)O(26)](4-) cluster. Isostructural compounds 11 and 12 have 3D polythread penetrated frameworks based on the delta-[Mo(8)O(26)](4-) polyoxoanion. The luminescent properties of the ligands and complexes 3, 6-8, and 11-12 are investigated in the solid state.

Synthesis of Three Novel Polyoxometalate–based Helical Hybrids from Simple to Complicated Helixes via Turing Metal Salt

“…The bond lengths around the Ag ions are in the ranges of 2.020(6)−2.136(6) Å for Ag−N, and 2.370(10) Å for Ag−O. These bond lengths and bond angles both are in the normal ranges …”

Three Organic–Inorganic Hybrids Based on [MoxOy]n– Chains Decorated with Organic Ligands and Transition‐Metal Coordination Complexes

“…Both contain infinite [Mo 8 O 26 ] n 4 n – inorganic POM chains. To date, three different linkage modes of the [Mo 8 O 26 ] n 4 n – 1D chains, based on the (γ‐Mo 8 O 26 ) 4– units, have been found: one‐corner shared,[12b] two‐corner shared,, , [12a] and bridge‐shared[7a], (as shown in Figure ).…”

“…In 1997, the Zubieta group reported 1D organic–inorganic hybrid materials of [(MoO 3 ) n (2,2′‐bipy) m ], in which 2,2′‐bipy was decorated in an (MoO 3 ) n 1D chain . Xu and Lu et al described an [Mo 3 O 10 ] n 2 n – infinite chain constructed from [Mo 3 O 10 ] trimers in several polyoxomolybdates modified with transition‐metal coordination complexes. Octamolybdatopolyanions [Mo 8 O 26 ] 4– have eight isomeric forms, α through θ .…”

Molybdenum-oxygen anionic chain grafted by Cu-phen complex. Synthesis, crystal structure and properties

“…The typical clusters are reported early, Mo 6 A survey of the reported compounds shows that there are many factors influencing the components and structures of the polymeric products, such as reactants ratio [20,28] and sort of reactants [23], reaction temperature which impacts both the composition and topology of the Mo-POM blocks [23,32]. Even at same condition three products were isolated and carefully adjusting the pH could obtain the single product [33]. That is, in aqua solution the polymerizing reaction of molybdate anions is very complicated and several equilibriums exist at the same time.…”