The cas register number of Dihydroethidium is 104821-25-2. It also can be called as 3,8-Phenanthridinediamine,5-ethyl-5,6-dihydro-6-phenyl- and the IUPAC Name about this chemical is 5-ethyl-6-phenyl-6H-phenanthridine-3,8-diamine. This chemical is photosensitive, so when you are using it, please keep under argon.

Physical properties about Dihydroethidium are: (1)ACD/LogP: 3.06; (2)ACD/LogD (pH 5.5): 2.93; (3)ACD/LogD (pH 7.4): 3.05; (4)ACD/BCF (pH 5.5): 92.67; (5)ACD/BCF (pH 7.4): 123.23; (6)ACD/KOC (pH 5.5): 820.07; (7)ACD/KOC (pH 7.4): 1090.5; (8)#H bond acceptors: 3; (9)#H bond donors: 4; (10)#Freely Rotating Bonds: 4; (11)Polar Surface Area: 9.72Ų; (12)Index of Refraction: 1.68; (13)Molar Refractivity: 99.6 cm³; (14)Molar Volume: 263.4 cm³; (15)Polarizability: 39.48x10^-24cm³; (16)Surface Tension: 55.3 dyne/cm; (17)Enthalpy of Vaporization: 86.81 kJ/mol; (18)Boiling Point: 580.4 °C at 760 mmHg; (19)Vapour Pressure: 1.83E-13 mmHg at 25°C.

You can still convert the following datas into molecular structure:
(1)SMILES: c4c(cc3c(c1c(cc(N)cc1)C(c2ccccc2)N3CC)c4)N
(2)InChI: InChI=1/C21H21N3/c1-2-24-20-13-16(23)9-11-18(20)17-10-8-15(22)12-19(17)21(24)14-6-4-3-5-7-14/h3-13,21H,2,22-23H2,1H3
(3)InChIKey: XYJODUBPWNZLML-UHFFFAOYAQ
(4)Std. InChI: InChI=1S/C21H21N3/c1-2-24-20-13-16(23)9-11-18(20)17-10-8-15(22)12-19(17)21(24)14-6-4-3-5-7-14/h3-13,21H,2,22-23H2,1H3
(5)Std. InChIKey: XYJODUBPWNZLML-UHFFFAOYSA-N