Theoretical and Experimental Study of New Photochromic Bis-Spiropyrans with Hydroxyethyl and Carboxyethyl Substituents

Table 1

Full energies including zero point energy correction 𝐸_tot + ZPE (a.u.) and relative energies Δ𝐸 (kcal/mol) of isomers (2a) and their oxazolidine forms calculated at the CPCM/PBE0/6-311G** level of theory (toluene solutions).

Structure	𝐸tot + ZPE, (a.u.)	Δ𝐸, (kcal/mol)
(2a)TTC-SP	−1681.720661	0
(2a)TTC-SP-ox	−1681.726102	−3.4
(2a)TTC-TTC	−1681.723617	−1.9
(2a)TTC-TTC-ox	−1681.712120	5.4