Metal complexes of saccharin

ICCC34 — golden edition of coordination chemistry reviews. Coordination chemistry for the neurosciences

The characterization of both the coordinated and non-coordinated saccharinate ion. The syntheses and crystal structures of aqua(2-formylpyridine thiosemicarbazonato)(saccharinato-N)copper(II) hemihydrate and 2,2′-bipyridyl-(2-formylpyridine thiosemicarbazonato)copper(II) saccharinate dihydrate

Jahn–Teller-active systems continue to yield unforeseen effects in the solid state. The use of conceptually simple potential energy surfaces, an approach developed by several investigators in recent decades, facilitates the understanding of diverse phenomena driven by Jahn–Teller activity. The background of this approach and its recent use in understanding dynamic Jahn–Teller systems, solid solutions of Jahn–Teller compounds in host lattices, and molecular shape switching in Jahn–Teller complexes are presented.

Jahn–Teller effects in solid-state co-ordination chemistry

Carbonic anhydrase IX (CA IX) is a target for hypoxic cancer therapies, and the discovery of CA IX selective ligands is imperative for the development of these agents. Primary sulfonamides are broad specificity inhibitors of CA enzymes, while secondary sulfonamides are generally poor CA inhibitors. However, saccharin, a cyclic secondary sulfonamide, has unusually good inhibition of CA IX (Ki = 103 nM). In this study, we demonstrate that the affinity and selectivity of saccharin for CA IX can be further modulated when linked to hydrophobic or hydrophilic substituents. The hydrophilic glycoconjugate derivative (12) showed improved inhibition of CA IX (Ki = 49.5 nM) and extremely poor inhibition of the predominant off-target CAs (Ki > 50 000 nM) compared to saccharin. This >1000-fold selectivity for CA IX over off-target CAs is unprecedented for classical primary sulfonamide CA inhibitors. Our study highlights the potential of cyclic secondary sulfonamides to be exploited for the discovery of potent, cancer-...

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Cyclic secondary sulfonamides: unusually good inhibitors of cancer-related carbonic anhydrase enzymes.

X-ray crystal structures of metalsaccharin complexes of general formula [M(C7H4NO3S)2(H2O)4]·2H2O, where M = Fe(II), Co(II), Ni(II) and Cu(II)

Zn compound\" M r = 5 3 7 . 8 2 , monoclinic, P2Jc, a = 7.939 (2), b = 16. 120 (2), c = 7.691 (2)/~, fl = 99.87 (2) °, V = 969.7 A 3, Z = 2, O m = 1.83, D x -1.84 g cm -3, Mo Kt~, ~. = 0.71069 ~, g = 14.7 cm -~, F(000) = 552, T = 294 (2) K. Cd compound: M r = 584.85, monoclinic, P2Jc, a = 8.036 (2), b = 16.145(3), c = 7 . 8 7 0 ( 1 ) A , f l = 1 0 0 . 2 4 ( 1 ) °, V = 1004.8 ,~3, Z = 2, D m = 1.92, D x = 1.93 gcm -3, Mo K~t, 2 = 0.71069 ,~, g = 12.4 cm -l, F(000) = 588, T = 294 (2) K. R = 0 . 0 2 8 and 0.025 for 1581 and * Saccharin is 1,2-benzisothiazol-3 (2H)-one 1,1-dioxide. \"t\" To whom correspondence should be addressed. 1850 intensities, respectively. The isostructural pair of complexes have centrosymmetric trans octahedral geometry. Delocalization of the charge away from the N atom may explain the weakness of the M N bond. The structures of the Cd H and Zn ~ compounds are compared with those involving Mn H, Fe II, Co H, Ni x~ and Cu ~I and trends in the metal-ligand M--N, M--OH 2 bond lengths are discussed. Introduction. We have described the syntheses and properties of a series of complexes with general formula [M(C7H4NO3S)2(H20)4].2H20 ( M M n Ix, Fe II, Co n, Ni II, Cu II and Zn II) (Haider, Malik & Ahmed, 1981; 0108-2701/84/071147-04501.50 © 1984 International Union of Crystallography 1148 [Zn(CTH4NO3S)2(H20)4].2H20 AND [Cd(CTH4NOaS)2(H20)4].2H20 Haider & Malik, 1982) and reported the crystal structure analyses of the Fe, Co, Ni and Cu complexes (Ahmed, Habib, Haider, Malik & Hursthouse, 1981; Haider, Malik, Ahmed, Hess, Riffel & Hursthouse, 1983). While our work was in progress an independent structural report of the corresponding Mn complex appeared (Kamenar & Jovanovski, 1982). In the present paper, we describe the crystal structure determinations of the Zn and Cd derivatives and discuss the structural variations in all seven related complexes. Experimental. Zn complex (ZNSAC) prepared as described earlier (Haider & Malik, 1982). Cd complex (CDSAC) prepared by reacting cadmium chloride with Na-saccharin in aqueous medium (Haider, Malik, Hursthouse & Wadsten, 1984). D m by flotation. Crystals suitable for X-ray work obtained by recrystallization from water. Lattice parameters determined by least-squares refinement of setting angles for 25 reflections [16 < 8(Mo K0t) < 17°], automatically centred on Enraf-Nonius CAD-4 diffractometer; intensity data recorded on same instrument, MoK~t radiation (graphite monochromator), following procedures described earlier (Hursthouse, Jones, Malik & Wilkinson, 1979). Semi-empirical absorption corrections applied to both data sets, using ~-scan values for 3 reflections in each case. Merging equivalent reflections and omitting those with F o < 3a(Fo) yielded 1581 (ZNSAC) and 1850 (CDSAC) unique data, which were used in structure analyses. Further experimental information is given in Table 1. Structures solved by heavy-atom method and refined by least squares. All non-hydrogen atoms refined anisotropically, hydrogen atoms (located from difference maps) isotropically. In final stage of refinement empirical isotropic extinction parameter x varied in modified expression for calculated structure factor, F c' = F~(1 x Fc2/sin8), and weighting scheme based on w = 1/[a2(Fo) + gFo 2] applied. Refinement on F converged at R =0.0281 (ZNSAC) and 0.0246 (CDSAC), with d / a < 0.1, absolute values of peaks and troughs in final difference maps <0.3e/% -3. Calculations performed on DEC VAXll /750 computer using S H E L X 7 6 (Sheldrick, 1976). Neutral-atom scattering factors from Cromer & Mann (1968) and Stewart, Davidson & Simpson (1965) for non-H and H atoms, respectively. Final atomic parameters and the bond lengths and angles involving the non-H atoms are given in Tables 2 and 3, respectively.* * Lists of structure factors, anisotropic thermal parameters, coordinates, bond lengths and angles involving the saccharinato hydrogen atoms, hydrogen-bond dimensions and data related to least-squares plane and dihedral angle calculations have been deposited with the British Library Lending Division as Supplementary Publication No. SUP 39313 (22 pp.). Copies may be obtained through The Executive Secretary, International Union of Crystallography, 5 Abbey Square, Chester CH 1 2HU, England. Table 1. Exper imenta l details

Structural studies of tetraaquabis(saccharinato-N)zinc(II) dihydrate, [Zn(C7H4NO3S)2(H2O)4].2H2O, and tetraaquabis(saccharinato-N)cadmium(II) dihydrate, [Cd(C7H4NO3S)2(H2O)4].2H2O

The preparatation and x-ray crystal structure of a saccharin complex of copper(II)

Mr= 665-74, triclinic, P), a = 16.428 (5), b=12.122(4), c=6.954(1)A, ct=97.61(2), fl= 77-36 (2), y=110.09(2) ° , V=1266.52A 3, Z=2, Dm(flotation ) = 1.72, D~= 1.74 g cm -3, /~(Mo Ka) = 6.3cm -1, 2=0.71069A, F(000)=676, T=294K, final R = 0.054 for 4724 reflections with F o > 3a(Fo). The structure consists of one Na ÷ and two independent K + cations, three independent C7HaNO3S - anions and one H20 molecule, in a polymeric framework. The anions are bonded to the cations through the N as well as the carbonyl and sulphonyl O atoms. The H20 molecule forms bridges between two Na + and between one Na ÷ and one K ÷ ion, and is also involved in H bonds with the carbonyl groups of two CvH4NO3S- anions.

http://journals.iucr.org/c/issues/1984/10/00/a23925/a23925.pdf

Dipotassium sodium trisaccharinate monohydrate, K2Na(C7H4NO3S)3.H2O

http://journals.iucr.org/c/issues/1985/01/00/a24480/a24480.pdf

[1,1'‐Diphenyl‐3,3'‐(ethylenediimino)di‐1‐butanonato]copper(II), [Cu(C22H22N2O2)] and [1,1'‐diphenyl‐3,3'‐(ethylenediimino)di‐1‐butanonato]palladium(II), [Pd(C22H22N2O2)]

S. Z. Haider

Papers

X-ray crystal structures of metalsaccharin complexes of general formula [M(C7H4NO3S)2(H2O)4]·2H2O, where M = Fe(II), Co(II), Ni(II) and Cu(II)

Structural studies of tetraaquabis(saccharinato-N)zinc(II) dihydrate, [Zn(C7H4NO3S)2(H2O)4].2H2O, and tetraaquabis(saccharinato-N)cadmium(II) dihydrate, [Cd(C7H4NO3S)2(H2O)4].2H2O

The preparatation and x-ray crystal structure of a saccharin complex of copper(II)

Dipotassium sodium trisaccharinate monohydrate, K2Na(C7H4NO3S)3.H2O

[1,1'‐Diphenyl‐3,3'‐(ethylenediimino)di‐1‐butanonato]copper(II), [Cu(C22H22N2O2)] and [1,1'‐diphenyl‐3,3'‐(ethylenediimino)di‐1‐butanonato]palladium(II), [Pd(C22H22N2O2)]