?-Chromophore-functionalized SWNTs by covalent bonding: substantial change in the optical spectra proving strong electronic interactionElectronic supplementary information (ESI) available: Fig. S1: UV-Vis-Near IR absorption spectra of a-SWNT-CO2H, b-SWNT-CO2H in DMF. Fig. S2: near IR absorption spectra of the intermediate NI, a-SWNT-NI, and b-SWNT-NI in CHCl3. Fig. S3: a possible resonance strucure of SWNT-NI. Fig. S4: luminescence excitation spectra monitored at 550 nm of a-SWNT-NI, b-SWNT-NI, the reference compounds NI-Ac, and NI. See http://www.rsc.org/suppdata/jm/b4/b405962j/