Tetrathiosquaric acid

Dithio-squaraines 37 can be synthesized via thionation of the correspondent oxo-squaraines 5 with phosphor pentasulphide or Lawesson reagent (Fig. 8) [103, 104], However, dithio-squaraines containing carboxylic groups cannot be obtained by this method. Symmetrical indolenine- and benzothiazole-based monothio- (38) and dithio- (37) squaraines containing carboxy and sulfo groups are synthesized using 1,2-dithio- and tetrathiosquaric acid, respectively, while the reaction of these... 

Multifunctional dithiolene ligands have been used to prepare binuclear as well as polymeric complexes. Some examples of this type of complex were already mentioned above (25 and 41) and involve the ligands benzenetetrathiol (51) or its alkyl ethers,78 the tetrathiosquaric acid (52), ethylenetetrathiol (53) and tetrathiooxalic acid (54) and its Se analog. The two-electron difference in oxidation state between (53) and (54) is much the same as that discussed for the parent dithiolene ligand. Crystallographic results (see Section 16.5.3.1) point out the equivalence of the latter two ligands. 

Tetraphosphine ligands, 995 Tetrapyridyls metal complexes, 91 geometry, 91 Tetrapyrroles metal complexes, 79 T etraselenoether metal complexes, 666 Tetrasulfur tetranitride metal complexes, 799 Tetrathiolane, bis(imino)-metal complexes, 591 Tetrathiooxalic acid metal complexes, 585, 606 Tetrathiosquaric acid metal complexes, 606 Tetrazole, 2-methyl-metal complexes, 77 Tetrazole, pentamethyl-metal complexes, 77 Tetrazoles metal complexes, 76 pK,ll... 

CiiH2K20S , Potassium tetrathiosquarate monohydrate, 42B, 98 C4H2K2O5, Potassium squarate monohydrate, 29, 674 Ci H20ii, Squaric acid (high-temp.), 43B, 165 C4H20 , Squaric acid, 39B, 89 40B, 131 41B, 156 43B, 165 C4H3KO5, Potassium 2-hydroxy-3,4-dioxocyclobut-1-ene-1-olate monohydrate, 39B, 90... 

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