Gallium and Indium Complexes of Bis(amino thiol) (N₂S₂) Ligands

Abstract

Three methods have been developed to prepare gallium and indium complexes of three tetradentate N(2)S(2) ligands of the general formula M(N(2)S(2))R (M = Ga, In; R = Cl, Br, SCN, O(2)CC(6)H(5)-O,O'). The ancillary ligand (Cl, SCN, O(2)CC(6)H(5)-O,O') was varied with the tetradentate ligand BAT-TM. X-ray crystallography shows that the coordination geometry about the d(10) metal ion is influenced by the steric requirements of the ligands. X-ray crystallography of four molecules results in the following data: GaCl(BAT-TM) (1), formula = C(10)H(22)ClGaN(2)S(2), space group = Pnma, a = 12.387(4) Å, b = 21.116(6) Å, c = 5.986(2) Å, V = 1565.8(9) Å(3), Z = 4; InCl(BAT-TM) (2), formula = C(10)H(22)ClInN(2)S(2), space group = Pnma, a = 12.968(9) Å, b = 29.29(1) Å, c = 5.866(2) Å, V = 1620(2) Å(3), Z = 4; InNCS(BAT-TM) (3), formula = C(11)H(24)ClInN(3)S(3), space group = Pbca, a = 11.812(3) Å, b = 11.679(3) Å, c = 24.238(9) Å, V = 3449.7 (17) Å(3), Z = 8; In(O,O'-O(2)CC(6)H(5))(BAT-TM) (4), formula = C(19)H(29)O(2)InN(2)S(2), space group = P2(1)/n, a = 10.783(2) Å, b = 18.708(4) Å, c = 12.335(4) Å, V = 2321.7(9) Å(3), Z = 4. Proton NMR studies show that the complexes are stable in solution; in polar solvents such as acetonitrile, for certain molecules, two metal-ligand complexes are observed. Similarly, two metal-ligand complexes are seen in NMR data taken in 80% acetonitrile/20% D(2)O (pD = 4.6) mixture. HPLC studies (acetonitrile/50 mM sodium acetate, pH = 4.6) show that the lipophilicity of the ligand determines the retention time of the complex.

Coordinating Radiometals of Copper, Gallium, Indium, Yttrium, and Zirconium for PET and SPECT Imaging of Disease

“…A similar structure was determined for the related GaCl- BAT-TM (GaCl- L4 ) except that chloride is the axial ligand (Figure 32). 132 In aqueous acetonitrile solution, however, NMR spectra revealed the presence of two different N 2 S 2 –coordinated species.…”

A novel gallium bisaminothiolate complex as a myocardial perfusion imaging agent

“…Gallium complexes of N 2 S 2 (bisaminoethanethiolate (1)) [26][27][28], as well as NS 3 [29], have been previously reported (Fig. 1).…”

Development of 68Ga ethyl cysteinate dimer for PET studies

“…On the other hand, gallium-N 2 S 2 complexes [19][20][21], as well as gallium-NS 3 complexes [22], have been previously reported. One unique feature of these Ga-complexes is that they have cationic character (?1-charged) in aqueous solution.…”