Crystal structure of tri-(1,4-bis(imidazol-1-yl)butane)-cadmium(II) dihexafluorophosphate, {[Cd(bimb)3](PF6)2}n, C30H42CdF12N12P2

Abstract

Source of materialA20mlH 2 Osolution of Cd(NO 3 ) 2 ×4H 2 O(0.154 g, 0.5mmol) and KPF 6 (0.184 g, 1.0mmol) was added to one leg of an "H-shaped" tube, and a2 0m lM eOH solution of bimb (1,4-bis(imidazol-1-yl)butane, 0.285 g, 1.5mmol) was added to the other leg of the tube.After threeweeks, the well-shaped colourless single crystals were obtained. Yield: 57%. Elemental analysis,found(%): C, 36.86; H, 4.24; N, 17.16; calcd.f or C 30 H 42 CdF 12 N 12 P 2 :C , 37.03; H, 4.35; N, 17.28%. IR data (cm -1 ): 3157w,1 520m, 1466w,1 405w,1 273w,1 235m,1 088m,9 34w,8 41vs,7 49m, 664w,556w. Experimental detailsTwo of the four crystallographic independant PF 6 -counter anions suffer from adisorder. DiscussionIn recent years, the design and synthesis of metal-organic frameworks (MOFs) with well-regulated architectures have caused increasing attention as they can be carried out as functional materials with potential applications in such fieldsasnonlinear optics, magnetism,m olecular separation, catalysis, luminescence, and gas sorption [1][2][3][4][5][6]. The ligands and metal centers both are the keys to the design and construction of metal-organic frameworks (MOFs) with fascinating topology and physicochemical properties [7,8].Flexible ligands are employed in the construction of metal-organic frameworks (MOFs) with variety of architectures and topologies because flexible ligands can adopt different conformations according to the geometric needs of the different metal ions [9,10]. The long flexible ligand 1,4-bis(imidazol-1-yl)butane (bimb)c an adopt various conformations with respect to the relative orientations of the CH 2 groups. Metal-organic frameworks (MOFs) containing bimb ligand exhibit avariety of architectures [11,12]. In this paper, we report on an ew coordination polymer{ [Cd(bimb) 3 ](PF 6 ) 2 } n based on the flexible ligand 1,4-bis(imidazol-1-yl)butane (bimb) andthe cadmium metal center. There are two crystallographically independentC d(II)a toms.B othC d(1) andC d(2) atomsa re locatedonthe threefold axis andeachofthemiscoordinated bysix imidazole nitrogenatoms from six bimb ligands. Thereare two crystallographically independent bimb ligands. All bimb ligands exhibit the anti-anti-gauche conformation. The torsion angles C1-C4 and C11-C14 of the butane chains of two independent bimb ligands are 175.4(4) and -174.6(4)°, respectively. Thedihedral angles between two imidazole ring planes are 23.7°for N1/N2/C5-C7 and N3/N4/C8-C10 and 23.0°for N5/N6/C15-C17 and N7/N8/C18/C20 imidazole ring planes. The butane chains C1-C4 and C11-C14 are both well coplanar with the mean deviation from the plane 0.0282 and 0.0330 Å, respectively. The planes of butane chains C1-C4 and C11-C14 acutely inclined, by 65.9 and 63.3°, to N1/N2/C5-C7 and N3/N4/C8-C10, 66.6 and 63.7°to N5/N6/C15-C17 and N7/N8/C18/C20 imidazole ring planes. The Cd-N bond lengths are in the ranges of 2.340 (3)