The third-order optical nonlinearity of metal(dmit)2 was investigated with femtosecond optical Kerr effect at 830 nm wavelength. The nonresonant second-order hyperpolarizability for the didodecyldimethylammonium–Au(dmit)2 (2C12–Au) molecule was estimated to be as large as 2.2×10−32 esu.

Conductive Langmuir-Blodgett films of ditetradecyldimethylammonium-Au(dmit)2 (dmit=1,3 dithiol-2-thione-4,5-dithiolate) have been fabricated without the use of matrix molecules. The in-plane dc conductivity was as high as 40 S/cm after electrochemical oxidation at room temperature. A metallic conductivity with a negative temperature derivative was observed in the temperature range of 250–300 K. At lower temperatures, the temperature dependence of the conductivity was of Arrhenius' type with an activation energy of 2.5 meV.

The conductive Langmuir-Blodgett (LB) film based on ditetradecyldimethylammonium-Au(dmit) 2 salt was studied. The film quality at the air/water interface was greatly improved by changing the "waiting time (T w )", which is defined as the time between the application of the spreading solution and the onset of compression. The main factor for the morphological improvement is considered to be the oxidation of the Au(dmit) 2 moiety at the air/water interface. The resultant conductivity of the LB film was highest in the case of T w = 30 min.

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