title: Novel mixed-valence Cu compounds formed by Cu(II) dimers with double oximato bridges: in situ formation of anionic layer [Cu2(SCN)3]n(n-).
abstract: Two new N3O donor ketoxime Schiff bases (HL(1) and HL(2)) have been synthesized by condensing N,N-dimethylethylenediamine with diacetylmonoxime and benzilmonoxime, respectively in a 1:1 ratio. Reaction of Cu(ClO4)2·6H2O with HL(1) resulted in a discrete oximato-bridged dinuclear Cu(II) complex [Cu2(L(1))2(H2O)2](ClO4)2 (1). The same reaction in presence of NaSCN affords the complex {[Cu(II)2(L(1))2][Cu(I)4(μ(1,3)-SCN)4(μ(1,1,3)-SCN)2]}n (2), where partial Cu(II)→Cu(I) reduction is observed. In 2, arrays of [Cu(II)2(L(1))2](2+) cationic units are inserted in between 2D {[Cu(I)4(SCN)6](2-)}n layers and connected via μ(1,1,3)-SCN(-) links, thus forming a 3D network. On the other hand, reaction of Cu(CH3COO)2 and HL(2) in the presence of NaSCN gave rise to a mixed-valence pentanuclear cluster {[Cu(II)2(L(2))2(NCS)]2[Cu(I)(SCN)(μ(1,1)-SCN)(μ(1,3)-SCN)]} (3) where Cu(II) is also partly reduced to Cu(I). In compound 3, two cationic [Cu(II)2(L(2))2(NCS)](+) units are bridged by the anionic [Cu(I)(SCN)3](2-) unit through long Cu-SCN linkages. The ligands and the complexes have been characterized by elemental analysis, UV/Vis and IR spectroscopy. The complexes are further characterized by single crystal X-ray diffraction and variable temperature magnetic (VTM) studies. Finally a complete magneto-structural correlation has been established between compounds 1-3 and all the characterized Cu dimers with a double NO bridge.
authors: Department of Chemistry, Jadavpur University, Raja S. C. Mullick Road, Kolkata 700032, West Bengal, India. samiranju92@gmail.com.
authors: Piu
authors: P
authors: Dhal
authors: Madhusudan
authors: M
authors: Nandy
authors: Dipali
authors: D
authors: Sadhukhan
authors: Ennio
authors: E
authors: Zangrando
authors: Guillaume
authors: G
authors: Pilet
authors: Carlos J
authors: CJ
authors: Gómez-García
authors: Samiran
authors: S
authors: Mitra
mesh_terms: D000838:Anions / Q000138:chemical synthesis / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D019281:Dimerization; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010091:Oximes / Q000737:chemistry*; D013861:Thiocyanates / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D000838:Anions; D009942:Organometallic Compounds; D010091:Oximes; D013861:Thiocyanates; D003300:Copper; C028631:cuprous thiocyanate