Gloria Pintus

New Symmetrical and Unsymmetrical Nickel-Dithiolene Complexes Useful as Near-IR Dyes and Precursors of Sulfur-Rich Donors

Abstract Novel symmetrical and unsymmetrical nickel dithiolene complexes based on a new ligand R2timdt (the -1 charged 1,3-dialkylimidazolidine-2,4,S-trithione) and dmit or mnt (dmit = 2-thioxo-1,3-dithiole-4,5-dithiolate; mnt = maleonitriledithiolate) useful as NIR-dyes and electrochromic materials in the 880-1400 nm region arc described here. The R2 timdt ligand, where N-electron donor atoms of the imidazoline ring are forced into co-planarity with the dithiolene ring, revealed to be valuable in shiftiig the low energy transition typical of this class of complexes in a region of remarkable interest for near-IR dyes, while stability was maintained. The symmetrical neutral complexes absorb very strongly at approximately 1000 nm, region of special interest for NIR-dyes in order to be used in Q-switching Neodymium lasers, which operate at 1064 nm. Moreover these complexes work as switchable NIR-dyes, since the absorption is shifted to approximately 1400 nm on reversible reduction. In the unsymmetrical nickel-dithiolcne complexes involving both the Pr2 itimdt and dmit or mnt ligands a tuning of the NIR-absorption depending on the combination of the ligands and of the charge is achieved.

A powerful new oxidation agent towards metallic gold powder: N,N′-dimethylperhydrodiazepine-2,3-dithione (D) bis(diiodine). Synthesis and X-ray structure of [AuDI2]I3

The oxidation of gold powder by a new safe and powerful oxidising reagent, the bis-diiodine adduct of N,N′-dimethylperhydrodiazepine-2,3-dithione (D), to produce [AuI2D]I3 under ambient conditions is described.

[Ni(R2pipdt)2](BF4)2 (R2pipdt = 1,4-disubstituted-piperazine-3,2-dithione) as useful precursors of mixed–ligand dithiolenes of interest for non-linear optics

A simple method to obtain in high yields mixed-ligand nickel-dithiolene complexes, which show strong negative solvatochromism and negative first molecular hyperpolarizability, and the use of Raman spectroscopy to establish the extent of electronic delocalisation in these complexes, are reported.

Unusual desulfurization of a nickel dithiolene by bis(2-diphenylphosphinophenyl)phenylphosphine (tp) to produce Ni(tp)(R4btimdt) [R4btimdt = 5,5′-bis(1,3-dialkyl-4-imidazolidine-2-thione-4-thiolate], the first complex of this class of ligands

A novel desulfurization reaction induced on the title nickel dithiolenes by a tripodal phosphine producing the first complex of the S,S-dianionic title ligand, which belongs to a novel family of redox active heterocycles, and the fully oxidised trimeric form of this ligand are described.