Chemistry of Water Soluble Carbon Nanotubes and Carbon Quantum Dots with Group IB Metal-Dithiolenes: Structural and Photophysical Insights

Abstract

A series of nanostructures of transition metal dithiolenes have been prepared and their interactions with CNTs and CQDs have been investigated. Silver(I) and copper(II)dithiolenes [PPh4]3[{Ag(mnt)}2I] (1) and [PPh4]2[Cu(mnt)2]2 (2) (mnt= maleonitriledithiolate) form nanospheres of diameters, 150 nm - 270 nm and gold(III) dithiolene [PPh4][Au(mnt)2]2 (3) forms doughnuts of diameter, 1.9 . The nanospheres of silver(I) dithiolene (1) interact with functionalized carbon nanotubes forming giant composite spheres (4) of diameter, 10.3 whereas the f-CNTs uniquely tie up doughnuts of gold dithiolene along the perimeter to form composite discs, (5). The nanospheres (1) interact with carbon quantum dots forming concave composite discs (7) filled with CQDs only at the central part. In the CQD-composite (8), gold(III) dithiolene interact with water soluble CQDs only along the perimeters. The EDX analysis of the nanospheres, doughnuts and the composite spheres confirm the presence of respective elements and proposed formulae. The X-ray structure analysis of the gold(IIII) dithiolene (3) reveals a unique lattice packing feature of a chain structure of [Au(mnt)2] anions encapsulating [PPh4] cations. Pure nano-microspheres of (1) are imaged as concave luminescent spheres whereas the f-CNT-composite spheres (4) and f-CQD composite spheres (7) are imaged as compact microspheres in the visible region.