Complexes of substituted benzothiazoles. 1. Cobalt(II), copper(II), and zinc(II) complexes of 2,2′-o-phenylenebisbenzothiazole; a potential N or S donor ligand

1979 ◽  
Vol 57 (1) ◽  
pp. 1-7 ◽  
Author(s):  
John Charles Thomas Rendell ◽  
Laurence Kenneth Thompson

A series of cobalt(II), copper(II), and zinc(II) complexes of the title ligand are reported. 1:1 complexes of cobalt and zinc, M(OBT)X2 (M = Co, Zn; X = Cl, Br, I, NCS), have four-coordinate pseudo-tetrahedral stereochemistries while for copper (X = Cl, Br), distorted square geometries are suggested. Six-coordinate 1:1 derivatives are also obtained for cobalt and copper, M(OBT)(NO3)2 (M = Co, Cu), while the 1:2 derivative Cu(OBT)2(ClO4)2-2H2O may be square planar. OBT appears to coordinate as an N2 donor in all cases. Preliminary X-ray data confirm a distorted square CuN2Cl2 structure for the copper chloride complex. Hydrogen bonded chloroform solvate molecules appear to be present in three cobalt complexes (X = Cl, Br, NCS).

2000 ◽  
Vol 55 (5) ◽  
pp. 373-376 ◽  
Author(s):  
Andrey B. Lysenko ◽  
Oleg V. Shishkin ◽  
Rostislav D. Lampeka

The 1:1 complex of palladium(II) chloride with 2-(2-methyl-3-phenyl-isoxazolidin-5-yl)- pyridine (L) has been prepared and studied by means of elemental analysis, 1H NMR spectroscopy and X-ray diffraction (monoclinic, space group P21/n with parameters: a = 8.141(2), b = 9.750(2),c = 20.691(6)Å ,β = 95.62(3)°,V = 1634.4(7)Å3 ,Z = 4 ;R1= 0.054 and wR2= 0.144 for 3352 unique reflections). A square-planar coordination polyhedron has been established for the palladium atom both in acetone solution and in the solid state. The organic ligand is coordinated toometal in a bidentate manner via nitrogen atoms of the pyridine substituent (Pd-N(2) 2.125(3) Å) and the isoxazolidine heterocycle (Pd-N(l) 2.102(3) Å). The other two coordination positions of palladium are occupied by chlorine atoms (Pd-Cl(l) 2.321(1) and Pd-Cl(2) 2.333(1) Å). The six-membered chelate ring formed by Pd, N(2), C(4), C(1), 0(1) and N (1) possesses a “twist-tub” conformation. The isoxazolidine cycle has an envelope conformation with an equatorial orientation of the methyl group.


2004 ◽  
Vol 57 (5) ◽  
pp. 483 ◽  
Author(s):  
Mark J. Robertson ◽  
Geoffrey A. Lawrance ◽  
Marcel Maeder ◽  
Peter Turner

The unsymmetric mixed-donor Nam,Npy,O-ligand N-trans-(2'-hydroxycyclohexyl)-2-aminomethylpyridine (pyca, 1) was readily prepared by reaction of an epoxide (cyclohexene oxide) with (2-aminomethyl)pyridine. The ligand forms octahedral bis-tridentate complexes, exemplified with isolation of copper(II), nickel(II), zinc(II), and cobalt(III) compounds; in addition, a square-planar palladium(II) complex with the ligand behaving as bidentate was prepared. The bis-tridentate octahedral complexes may exist in six geometric isomeric forms, and molecular mechanics analysis was employed to predict the most stable isomer for copper(II), nickel(II), and cobalt(III) complexes. For the copper(II) and cobalt(III) complexes, the predictions match the X-ray crystal structures of the single isomer isolated in each case. Both the copper(II) complex [Cu . 12](ClO4)2 and the cobalt(III) complex [Co . 1 . (1–H)](ClO4)2 crystallized in the monoclinic space group P21/n (no. 14), with a 9.8400(13), b 15.434(2), c 10.0180(13) Å, and β 109.004(2)°, and a 14.162, b 18.583, c 21.596 Å, and β 100.04°, respectively. Both complexes adopt distorted octahedral structures. The copper(II) complex exists as the all-trans-fac isomer with Jahn–Teller elongation of the Cu–O bond [2.3795(19) Å] compared to Cu–Npy [2.040(2) Å] and Cu–Nam [2.024(2) Å] distances. The cobalt(III) complex appears as the cis,cis,trans(Npy) fac isomer, but deprotonation of one of the two alcohol groups leads to all six M–L distances differing: for each of two similar independent complex cations, Co–O [e.g. 1.9123(16), 1.9459(16) Å], Co–Nam [e.g. 1.949(2), 1.968(2) Å], and Co–Npy [e.g. 1.938(2), 1.940(2) Å] vary, with particularly the deprotonated alcohol bond significantly shorter than the protonated bond, despite a strong hydrogen bonding interaction with the protonated alcohol in the partner complex cation in the unit cell.


1988 ◽  
Vol 41 (2) ◽  
pp. 159 ◽  
Author(s):  
JM Harrowfield ◽  
JM Patrick ◽  
BW Skelton ◽  
AH White

X-ray structural studies of both products and reactants involved in the template formation of the macrocycle 'cyclars' (5,14-dimethyl-5,6- 7,9,14,15,16,18-octahydrodibenzo[e,l]- dithiadiarsacyclotetradecin ) have been performed, and the results used to define several aspects of possible reaction mechanisms. The structure of the racemic form of cyclars shows that this free arsenic/sulfur donor ligand is not 'preorganised' for square-planar coordination, though metal ion/donor atom distances in its palladium(II) complex (Pd-As 2.388 Ǻ, Pd-S 2.314 Ǻ) do appear normal. In contrast, the structure of the palladium(II) complex of the arsenic meso ligand, which is not a direct product of the template reaction, shows relatively short palladium/donor atom distances (Pd-As 2.361 Ǻ, Pd-S 2.278 Ǻ), suggesting that template formation may be inhibited because the 'hole size' of this ligand diastereomer is too small for palladium(II). Further, the structure of a bis (bidentate) ligand precursor complex which could, in principle, generate the meso macrocycle shows that, in the solid at least, the reactant groups are not favourably juxtaposed for cyclization. The structure of the platinum(II) complex of a sulfenate derivative of the same bidentate ligand suggests that electrophili c attack at coordinated thiolate, the crucial step in the macrocycle formation, is completely unselective for an unconstrained electrophile.


2020 ◽  
Vol 76 (2) ◽  
pp. 133-138
Author(s):  
Wen-Tong Chen

Porphyrins and metalloporphyrins can generally show attractive structural motifs and interesting properties. A new copper porphyrin, namely poly[[μ-chlorido-[μ5-5,10,15,20-tetrakis(pyridin-4-yl)-21H,23H-porphine]tricopper(I)] [aquadichloridocopper(II)]], {[Cu3(C40H24N8)Cl][CuCl2(H2O)]} n (1), was synthesized by the self-assembly of copper chloride with 5,10,15,20-tetrakis(pyridin-4-yl)-21H,23H-porphine under solvothermal conditions. The structure of this copper porphyrin was characterized by single-crystal X-ray crystallography and elemental analysis. The porphyrin macrocycle shows a distorted saddle geometry, with the four pyrrole rings slightly distorted in an alternating mode either upwards or downwards. The copper ions show three-coordinated triangular and four-coordinated square-planar geometries. Every copper–porphyrin unit connects to 12 others via four μ4-bridging Cu2Cl moieties to complete the three-dimensional framework of compound 1, with isolated CuCl2(H2O) units located in the voids. This copper porphyrin displays a red photoluminescence. Electrochemical measurements showed that compound 1 has two redox waves (E 1/2 = −160 and 91 mV).


2019 ◽  
Author(s):  
KAIKAI MA ◽  
Peng Li ◽  
John Xin ◽  
Yongwei Chen ◽  
Zhijie Chen ◽  
...  

Creating crystalline porous materials with large pores is typically challenging due to undesired interpen-etration, staggered stacking, or weakened framework stability. Here, we report a pore size expansion strategy by self-recognizing π-π stacking interactions in a series of two-dimensional (2D) hydrogen–bonded organic frameworks (HOFs), HOF-10x (x=0,1,2), self-assembled from pyrene-based tectons with systematic elongation of π-conjugated molecular arms. This strategy successfully avoids interpene-tration or staggered stacking and expands the pore size of HOF materials to access mesoporous HOF-102, which features a surface area of ~ 2,500 m2/g and the largest pore volume (1.3 cm3/g) to date among all reported HOFs. More importantly, HOF-102 shows significantly enhanced thermal and chemical stability as evidenced by powder x-ray diffraction and N2 isotherms after treatments in chal-lenging conditions. Such stability enables the adsorption of dyes and cytochrome c from aqueous media by HOF-102 and affords a processible HOF-102/fiber composite for the efficient photochemical detox-ification of a mustard gas simulant.


1985 ◽  
Vol 50 (6) ◽  
pp. 1383-1390
Author(s):  
Aref A. M. Aly ◽  
Ahmed A. Mohamed ◽  
Mahmoud A. Mousa ◽  
Mohamed El-Shabasy

The synthesis of the following mixed ligand complexes is reported: [Ni(phdtc)2(dpm)2], [Ni(phdtc)2(dpe)2], [Ni(phdtc)2(dpp)3], [Ni(1-naphdtc)2(dpm)2], [Ni(1-naphdtc)2], and [Ni(1-naphdtc)2(dpp)2], where phdtc = PhNHCSS-, 1-naphdtc = 1-NaPhNHCSS-, dpm = Ph2PCH2PPh2, dpe = Ph2P(CH2)2PPh2, and dpp = Ph2P(CH2)3PPh2. The complexes are characterised by microanalysis, IR and UV-Vis spectra, magnetic measurements, conductivity, X-ray powder diffraction, and thermal analysis. All the mixed ligand complexes are diamagnetic, and thus a square-planar or square-pyramidal (low-spin) structure was proposed for the present complexes.


2008 ◽  
Vol 73 (1) ◽  
pp. 24-31
Author(s):  
Dayu Wu ◽  
Genhua Wu ◽  
Wei Huang ◽  
Zhuqing Wang

The compound [Cd(4,4'-bpy)2(H2O)2](ClO4)2·(L)2 was obtained by the reaction of Cd(ClO4)2, bis(1-pyrazinylethylidene)hydrazine (L) and 4,4'-bipyridine in aqueous MeOH. Single-crystal X-ray diffraction has revealed its two-dimensional metal-organic framework. The 2-D layers superpose on each other, giving a channel structure. The square planar grids consist of two pairs of shared edges with Cd(II) ion and a 4,4'-bipyridine molecule each vertex and side, respectively. The square cavity has a dimension of 11.817 × 11.781 Å. Two guest molecules of bis(1-pyrazinylethylidene)hydrazine are clathrated in every hydrophobic host cavity, being further stabilized by π-π stacking and hydrogen bonding. The results suggest that the hydrazine molecules present in the network serve as structure-directing templates in the formation of crystal structures.


CrystEngComm ◽  
2014 ◽  
Vol 16 (22) ◽  
pp. 4783-4795 ◽  
Author(s):  
Biswajit Bhattacharya ◽  
Debraj Saha ◽  
Dilip Kumar Maity ◽  
Rajdip Dey ◽  
Debajyoti Ghoshal

2015 ◽  
Vol 70 (12) ◽  
pp. 851-856 ◽  
Author(s):  
Chun-Hua Dai ◽  
Fu-Lin Mao

AbstractThe tridentate N-donor ligand 2,6-di(2-oxazolyl)pyridine (L) reacts with AgClO4 and AgPF6 to yield two new complexes, {[Ag5(L)5](ClO4)5}n (1) and {[Ag5(L)5](PF6)5}n (2), which have been characterized by single-crystal and powder X-ray diffractions, IR spectroscopy, and elemental and thermogravimetric analyses. Complexes 1 and 2 are isotypic, displaying helical chain structures. The fluorescence properties of 1 and 2 were investigated.


Polyhedron ◽  
2005 ◽  
Vol 24 (8) ◽  
pp. 865-871 ◽  
Author(s):  
Mohan S. Bharara ◽  
Chong H. Kim ◽  
Sean Parkin ◽  
David A. Atwood

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