A novel photosensitizer based on a ruthenium(ii) phenanthroline bis(perylenediimide) dyad: synthesis, generation of singlet oxygen andin vitrophotodynamic therapy

Abstract

In this study, a novel photosensitizer having two perylenediimide units and a phenanthroline ruthenium(ii) coordination moiety (Ru-BP) has been developed for photodynamic therapy (PDT) of cancer cells.

Desymmetrization of Perylenediimide Bay Regions Using Selective Suzuki–Miyaura Reactions from Dinitro Substituted Derivatives

“…Preparation of dyad 6: The general procedure was followed starting from regioisomeric mixture PDI-(Br) 2 2 (110 mg;0 .155 mmol) and using 4-(diphenylamino)phenylboronic acid 4 (45 mg;0 .155 mmol), K 3 PO 4 (66 mg;0 .31 mmol) as the base in THF (9 mL)/H 2 O( 1mL) mixture. The reaction afforded am ixture, which was purified by silica gel column chromatography using CH 2 Cl 2 /petroleum ether (3:2) to CH 2 Cl 2 as the eluent: (1,6)-PDI-(TPA) 2 and (1,7)-PDI-(TPA) 2 regioisomers (67 mg;4 3% yield) and the mixture of inseparable (1,6) and (1,7)-TPA-PDI-Br 6 regioisomers (ratio 1:1) (24 mg;1 5% yield) were obtained.…”

“…The electrochemical behavior of the triads was investigated by cyclic voltammetry performed in CH 2 Cl 2 with 0.1 m nBu 4 PF 6 after adjustingt he measured E red 1=2 to the level of the Fc + /Fc couple (Figure 5b and Ta ble 2). The regioisomers 5-(1,6) and 5-(1,7) demonstrated comparable electrochemical properties, with two reduction waves around À1.1 and À1.3 V( vs. Fc + /Fc) attributed to the formation of radical anion and dianion of the PDI unit, respectively,b eing slightly lower for regioisomer (1,6). To wardp ositive potentials, they exhibited ao ne two-electron reversible oxidationw ave at + 0.56 V, generatingt he double cationic speciesT PA + C-PDI-TPA + C.T he oxidation potential of regioisomer (1,6)w as found to be slightly higher than that of (1,7).…”

“…Decoration of the PDI core with CÀCl inked aromatic or conjugated derivatives requires prior halogenation of the bay (1,6,7,12) position(s), meta to the imide groups with respect to Holleman rules, [9] followed by ap alladium catalyzed cross-coupling reaction. Particular attention has been paid to the bisfunctionalization of PDI leading to amixture of 1,6-and 1,7-regioisomers, [10] which breaks the planarityo ft he system and maintains its electron-accepting capabilities.R emarkably,different characteristics can arise from separate 1,6-or 1,7-regioisomers, such as spectroscopica nd electrochemical properties and even photovoltaic performance.…”

“…We demonstrate that the special reactivity of dinitro PDIs, which are more easily prepared than the dibromo analogs,e nables efficient access to asymmetricP DI-centered triads. Highly straightforward and selective sequential SMC reactions lead to PDI centered donordonor'( D-PDI-D') or donor-acceptor (D-PDI-A) triads, (1,6) and (1,7) regioisomers, which weres eparated and independently characterized.…”

“…(1,6): R f = 0.61 in CH 2 Cl 2 /petroleum ether (3:2) 1. HNMR (CDCl 3 , 500 MHz): d = 8.57 (s,2 H), 8.22 (d, J = 8.1 Hz, 2H), 7.98 (d, J = 8.1 Hz, 2H), 7.35-7.32 (m,8 H), 7.24-7.19 (m,1 2H), 7.13-7.08 (m, 8H), 5.07-4.99 (m,2H), 2.61-2.50 (m,4H), 1.93-1.88 (m,4H), 1.78-1.72 (m,6 H), 1.51-1.42 (m,4 H), 1.35-1.30 ppm (m,2 H).…”