Polymeric nickel(II) squarate complexes with imidazole derivatives: syntheses, crystal structures, spectroscopic and voltammetric studies

μ-Squarato-κ2O1:O2-bis{[2-(2-aminoethyl)pyridine-κ2N,N′]aquanickel(II)} squarate 0.25-hydrate

“…The geometry about Ni II ion centre is a slightly distorted octahedron, the six coordination sites being occupied by four N atoms from two chelating aepy ligands and two O atoms from squarate and aqua ligands. The observed Ni1-N, Ni1-O bond distances and N-Ni1-N, N-Ni1-O and O-Ni1-O bond angles are generally consistent with those observed in related Ni II squarate complexes [Uçar, 2008;Kirchmaier et al, 2003].…”

“…For general background, see: Bernardinelli et al (1989); Bulut et al (2004); Castro et al (1995Castro et al ( , 1997; Crispini et al (2000); Kirchmaier et al (2003); Lee et al (1996); Milet et al (2003); Solans et al (1990); Spek (2003); Trombe et al (2002); Uçar (2008); Uçar et al (2006Uçar et al ( , 2007; Yang et al (2003). (2) 172(3) N4-H4BÁ Á ÁO2 ii 0.88 (2) 2.52 (2) 3.078 2122.6 (18) N4-H4BÁ Á ÁO6 0.88 (2) 2.52 33.350 (2) 158(2) N4-H4AÁ Á ÁO4 iii 0.86 (2) 2.27 (2) 3.091 (2) 161 (2) N2-H2BÁ Á ÁO3 iv 0.83 (2) 2.14 (3) 2.963 (2) 169 (2) Symmetry codes: (i) x; Ày þ 2; z þ 1 2 ; (ii) x; y À 1; z; (iii) x; Ày þ 1; z þ 1 2 ; (iv) Àx þ 1 2 ; y À 1 2 ; Àz þ 1 2 .…”

Polynuclear and polymeric squarato-bridged coordination compounds

“…This category represents not only the major species for the bis-μ 1,3 but also for the rest of the bridging-squarato compounds. It includes mono-squarato catena -[M II (μ 1,3 -C 4 O 4 )(DMSO) 2 (H 2 O) 2 ] 37–65 {M = Mn, Co, Zn ( 18–20 )}, 37 catena -[Cu 2 ( 2 , 2 ′- bpy ) 2 (μ 1,3 -C 4 O 4 )(μ-OH) 2 ]·4H 2 O ( 21 ), 35 b [M II (L) x (μ 1,3 -C 4 O 4 )(H 2 O) y ] 37–65 where L = py, x = y = 2: M = Co, Ni, Cu, Zn ( 22–25 ); 38 L = H 2 O, x = y = 2: M = Mn, Fe, Co, Ni, Cu, Zn ( 26–30 ); 27,42 L = 4-Meim: M = Co, Ni, Cd, x = y = 2 ( 31–33 ); 44,46 L = 2-Meim, M = Co, x = y =2 ( 34 ); 46 L = 4-pyca, x = y =2: M = Co, Cu ( 35 , 36 ); 49 L = DMF: M = Mn, Co, Ni, Cu, Zn, x = y = 2 ( 37–41 ); 51,52 L = pz, M = Ni, x = y =2 ( 42 ); 51,52 L = 1-Meim, x = y =2: M = Zn, Cd ( 43 , 44 ); 53 L = bpp, x = y = 2: M = Mn, Fe, Co 45–47 ); 54,55 L = im, x = y = 2: M = Co, Cu, Zn ( 48–50 ); 27,56 L = DPA, M = Zn, x = y =1 ( 51 ); 11 L = Me 4 en, x = 1, y = 2, M = Ni ( 52 ); 45 L = 3-pypz, x = 2, y = 0, M = Cd ( 53 ); 48 L = L 1 , x = 2, y = 0, M = Cu ( 54 ); 57 L = L 2 , x = 2, y = 0, M = Ni ( 55 ); 44 L = L 3 , x = y = 1, M = Cu ( 56 ); 58 L = pic, x = 2, y = 0: M = Cu, Zn, Cd ( 57–59 ); 59 a L = ea, x = 2, y = 0, M = Cu ( 60 ); 60 L = 2-pEtOH, x = 2, y = 0, M = Cu ( 61 ); 61 L = bimam, x = 2, y = 0, M = Cu ( 62 ) 62 and catena -[Cu 2 (bimam) 2 (μ 1,3 -C 4 O 4 )Cl 2 ] ( 63 ), 63 as well as bis-squarato catena -[M II (μ 1,3 -C 4 O 4 ) 2 (H 2 O) 2 ] 2− (M = Ni, Cu, Zn, Mn and Cd ( 64–68 )) complexes. …”