Dithiolene derivatives have become a ligand of interest due to their structural diversity, redox behavior, and other physical properties depending on the metal coordinated. One of the properties being studied is the high near infrared (NIR) absorption of metal bis(dithiolene) complexes, and how to improve it with the functionalization. The absorption coefficient could be increased by functionalizing the dithiolene with other NIR-photoactive species such as benzenes and other aromatic compounds. A new 1,2-dithiolbenzene ligand, that is 3,4-dimercapto-N-(3-(triethoxysilyl) propyl) benzamide, APTES-C7H5S2, is prepared from 4-methyl-1,2-dithiolbenzene (C7H8S2). The interest behind this new ligand is that both ends can bind or coordinate with metal compounds. Dithiolates can coordinate to metal ions such as Ni2+, Mn2+, Fe2+, and others, which is the rationale for this research. As for the silicates, they have shown to have high affinity to metal oxide nanoparticles and to improve their water dispersibility. The synthesis of the ligand started with the protection of the thiol groups by reacting of C7H8S2 with benzoyl chloride in basic conditions, to prevent the formation of disulfide bonds, forming S, S’-(4-methyl-1,2-phenylene) dibenzothioate (C7H6S2(COPh)2). Afterwards, the methyl group was able to be oxidized to produce the benzoic acid that later acted as an anchor for the 3-triethoxysilylpropylamine (APTES) group. The intermediates structures were confirmed with H1-NMR, C13-NMR and FTIR. Finally, in a one-pot reaction the deprotection of the thiol group was done and the coordination of the dithiolate to nickel was done, producing a chiral metal complex. This poster will show the characterization of C7H6S2(COPh)2 the in the H1-NMR the absence of the hydrogen singlet of the thiol and in C13-NMR the downfield shift of the carbon of the C=O bond will confirm the new S-C=O bond. Also, for the oxidized form of C7H6S2(COPh)2 in the FTIR the vibration of O-H around 3300 cm-1 will confirm the oxidation. Finally, for the protected form of APTES-C7H5S2 the characterizations will show the C-N of the amide formed.

Synthesis and characterization of silicate functionalized dithiolene derivative

ACS Spring 2022

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