Fig. 1. Raman spectra of C—N in pure DMF (a) and 0.84 mol·L^-1 CuCl₂/DMF (b) at different temperatures

Fig. 2. MW2D Raman spectra of C—N in pure DMF (a) and0.84 mol·L^-1 CuCl₂/DMF (b) at temperature range 25~81 ℃

Fig. 3. 2D Raman spectra of C—N in pure DMF and 0.84 mol·L^-1 CuCl₂/DMF under temperature disturbance
(a): Synchronous 2D Raman in pure DMF; (b): Asynchronous 2D Raman in pure DMF;(c): Synchronous 2D Raman in CuCl₂/DMF; (d): Asynchronous 2D Raman in CuCl₂/DMF

Fig. 4. B3LYP optimized the possible structures of (DMF)₂ and [Cu(DMF)_n]²⁺(n=1~6)