Study On Syntheses, Crystal Structure And Properties Of Hybrid Cyano-bridged Heterobimetallic Prussian Blue Complexes Which Contain Imidazole Ligands | | Posted on:2010-08-15 | Degree:Master | Type:Thesis | | Country:China | Candidate:S F Tong | Full Text:PDF | | GTID:2121360302965005 | Subject:Inorganic Chemistry | | Abstract/Summary: |  PDF Full Text Request | | In this thesis, seven complexes [Na(H2O)4][Cu(B2IG)]2[Fe(μ-CN)2(CN)4]·CH3OH·3H2O (1), [Na6O2(OH)2][Cu(B2IG)]4[Fe(μ-CN)4(CN)2]·4H2O (2), [K(H2O)4 ] [(Cu(B2IA))2(Fe(μ-CN)2(CN)4]2·(H3O)·15H2O (3), [Na2(H2O)8][Cu(B2IA)]2 [Fe(μ- CN)2(CN)4]·6H2O (4), [Cu(B2IG)]3[Cr(μ-CN)3(CN)3]·11H2O (5), [K(H2O)4][(Cu(B2 IA))2 (Cr(μ-CN)2(CN)4]2·(H3O)+·15H2O (6), and [K(H2O)4] [(Cu(B2IA))2(Co(μ-CN)2 (CN)4]2·(H3O)+·15H2O (7) have been synthesized, (B2IG = N,N-Bis(2-(1- methylimidazolyl)methyl)methyl)glycine, B2IA = N, N-Bis(2-(1-methylimidazolyl) methyl)methyl)-β-alanine), and characterized by infrared spectroscopy (IR), electron spray mass spectrometry (ESMS), cyclic voltammetry (CV), X-ray diffraction analys- is, M·ssbauer spectroscopy, electrical conductivity and variable temperature suscept- ibility, respectively.The results of single-crystal analysis show that in Hybrid Prussian blue compl- exes {[M(L)]m+}x{[[B(CN)6]k-}y ( B = Fe, Co, Cr ; [M(L)]m+ = ([Cu(B2IG)]NO3)n, [Cu2 (B2IA)2]Na(NO3)3·(H2O)2 ), 1 and 4 are trinuclear complexes, in which each two [Cu(L)]+ ions is linked to [Fe(CN)6]3- unit in trans positions; 2 is pentanuclear complex; 3, 6 and 7 are hexanuclear complexes through the K+ bridge; 5 is tetranuclear complex, three [Cu(L)]+ ions is linked to the [Cr(CN)6]3- unit in cis positions. Two-dimensional network structures are formed via hydrogen bonds in 1, 3 and 6 complexes; 2 has a three-dimensional layers structure via hydrogen bonds andππinteractions; 4 and 7 have a three-dimensional layers structure via hydrogen bonds; 5 shows a three-dimensional network space packing structure via hydrogen bonds andππinteractions;. The center atoms B (B = Fe, Co, Cr) have a slightly distorted octahedral geometry. The copper atoms have formed a slightly distorted square-pyramidal coordination conformation except Cu1,Cu2 for the complex 5 in which are a distorted trigonal bipyramid.The results of variable temperature susceptibility indicate that the complex 1 appears ferromagnetic property in the range from 2 to 300 K, following the Curie–Weiss law with a Weiss constantθ= 4.79 K; the complex 2 appears antiferromagnetic property in the range from 30 to 300 K, and weak ferromagnetic coupling from 4 to 30 K; the complex 4 appears antiferromagnetic property from 2 to 300 K; the structures of the complex 3, 6 and 7 are similar, the magnetic properties are similar too, they appear antiferromagnetic propert, following the Curie–Weiss law with a negative Weiss constantθ(3 and 7), and the antiferromagnetic coupling became weak or turned to ferromagnetic coupling from 5 to 75 K.Data from the changes ofν(C≡N) stretch, the room-temperature magnetic moment (μeff) and the Mossbauer spectroscopy at room temperature show the complexes 1 and 3 have a typical spin state for LS FeIII, the complex 2 has a typical spin state for LS FeII, the complex 4 has a typical spin state for HS FeII, the complex 6 has a typical spin state for LS CrIII, the complex 7 has a typical spin state for LS CoIII. The oxidation state of iron ions for 2 and 4 have changed from +3 to +2.The result from electrical conductivity research indicates that the conductance is 0.77×10-7 S/cm for the complex 2, which appears semiconductor property.
| | Keywords/Search Tags: | Complex, Prussian Blue, Cyanid, Imidazole, Crystal Structure, Magnetism | | PDF Full Text Request | Related items |
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