The saccharinate anion: a versatile and fascinating ligand in coordination chemistry

Abstract

Recebido em 14/6/04; publicado na web em 12/11/04The saccharinate anion, obtained by deprotonation of the N-H moiety of saccharin (o-sulfobenzimide) is a very versatile and polyfunctional ligand in coordination chemistry. In this review the different forms of metal-to-ligand interactions involving this anion and some other coordination peculiarities are briefly discussed on the basis of some selected examples.

Oxidative-addition of the N–H bond of saccharin (sacH) to a triosmium centre: Synthesis, structure and reactivity of Os3(CO)10(μ-H)(μ-sac)

“…The coordination chemistry of the sac has been extensively investigated revealing its versatile coordination properties as it possesses four donor atoms to bind with transition metal centres -one nitrogen and three oxygens (one carbonylic and two sulfonic) [2]. Although it can bind to transition metals in a number of different ways using these donor atoms, the simple Nbound coordination (I in Chart 1) is by far the most commonly observed [2,3].…”

Investigations into the Mechanism of Solvolysis of 3-aryloxybenzisothiazoles

“…36 Considering that bond lengths are related to reactivity and electronegativity, 30,31 differences in the relative ether bond lengths for ethers 6 (R = 4-NO 2 and R = 4-CH 3 O) could also be hypothesized. However, analysis of reported bond lengths and angles for these ethers, obtained by X-ray crystallography, shows that the ether bond lengths C 3 −O 4 and O 4 −C 5 are 133.5 and 141.7, and 133.1 and 142.4 pm respectively, revealing no significant difference with the electronic nature of the substituent on the aryl ring, in the crystal. 35 Thus, the opposite electronic effects of nitro and methoxy substituents have no opposed effect on the C 3 −O 4 −C 5 bond lengths, and the explanation for different chemical behaviour in solvolysis of these ethers cannot be found in groundstate electronic features in the crystal.…”

“…The parent compound, saccharin (1,2-benzisothiazol-3(2H)-one1,1-dioxide), 1 is a commonly known substance and the oldest artificial sweetener. 2 Moreover, saccharin and its anion, saccharinate, act as ligands in coordination chemistry 3,4 and have recently been considered for the formulation of amide-based ionic liquids. 5−8 Some saccharyl derivatives show biological activity, such as herbicidal, 9,10 antimicrobial and antifungal, 11−14 potential in enzymatic inhibition 15 or anti-HIV-1 activity.…”

A comparative study of the coordination of saccharinate (sac), thiosaccharinate (tsac) and benzisothiazolinate (bit) ligands to trans-[PdCl2(H2NBz)2]: molecular structure of cis-[Pd(bit)2(H2NBz)2]

“…1) are versatile poly-functional ligands, shown to adopt a variety of coordination modes, and consequently their coordination chemistry has been widely studied [1,2]. Palladium(II) and platinum(II) complexes of these ligands have been detailed [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] with some showing promising biological properties [19][20][21][22][23][24].…”

“…Griffith and co-workers have reported the synthesis of cis-[Pd(N-bit) 2 (j 2 -en)] (en = ethylenediamine) and [Pt(NH 3 ) 2 (N-bit) 2 ], the former being characterised by single-crystal X-ray crystallography [25], while we have recently detailed the synthesis of a number of square-planar palladium complexes, trans-[Pd(N-bit) 2 L 2 ], with amine, amide and diphosphine co-ligands [26]. The latter can be formed via two synthetic routes, namely reaction of [Pd(bit) 2 …”