DFT Study of Binding and Electron Transfer from a Metal-Free Dye with Carboxyl, Hydroxyl, and Sulfonic Anchors to a Titanium Dioxide Nanocluster

Table 5

Distances, in Å, and angles, in ^o, relevant to the binding primarily through the –OH group of the dye to the nanocluster. O_D–H and H–O_S refer to the distances between the H3 proton and the adjacent oxygen atom on the dye and on the substrate, respectively. The geometry was optimized at DFT/B3LYP/3-21G(d) level.

	H1-ACY^2−	H3-ACY^2−	H1H3-ACY^−
𝑟(Ti–O)	1.880	1.832	1.855
𝑟(Ti–O′)	2.063	2.020	1.932
𝑟(Ti–O′′)	2.029	—	—
𝑟(OD–H)	—	1.082	1.504
𝑟(H–OS)	—	1.462	1.060
ψ	89.54	95.17	92.49
θ	16.96	29.35	33.58
φ	28.12	11.53	10.45