title: Solvation dynamics of DCM in a DPPC vesicle entrapped in a sodium silicate derived sol-gel matrix.
abstract: Solvation dynamics of 4-(dicyanomethylene)-2-methyl-6(p-dimethylaminostyryl) 4H-pyran (DCM) has been studied in a dipalmitoyl-phosphatidylcholine (DPPC) vesicle entrapped in a sodium silicate derived sol-gel glass. Solvation dynamics in DPPC in a sol-gel glass is described by two components of 350 +/- 50 ps (50%) and 2300 +/- 200 ps (50%) with a total dynamic Stokes shift of 1300 cm(-1). The fast component (350 ps) is similar to the fast component in a DPPC vesicle in bulk water (320 +/- 50 ps). This component may be ascribed to the dynamics of the water molecules inside the water pool of the vesicle. However, the slow component (2300 +/- 200 ps) is about 2.5 times slower compared to the slow component of solvation dynamics of DCM in a DPPC vesicle in bulk solvent (900 +/- 100 ps). The anisotropy decay of DCM in a DPPC vesicle both in sol-gel glass and in bulk water exhibits a very fast initial decay with a large residual anisotropy, which does not decay in approximately 10 ns. The time scale of anisotropy decay is very different from that of solvation dynamics.
authors.affiliation: Physical Chemistry Department, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India.
authors.forename: Pratik
authors.initials: P
authors.lastname: Sen
authors.forename: Saptarshi
authors.initials: S
authors.lastname: Mukherjee
authors.forename: Amitava
authors.initials: A
authors.lastname: Patra
authors.forename: Kankan
authors.initials: K
authors.lastname: Bhattacharyya
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry*; D016880:Anisotropy; D002621:Chemistry / Q000379:methods; D002627:Chemistry, Physical / Q000379:methods; D008956:Models, Chemical; D044367:Phase Transition; D011714:Pyrans / Q000737:chemistry*; D017640:Silicates / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013343:Styrenes / Q000737:chemistry*; D013696:Temperature; D013816:Thermodynamics; D013997:Time Factors
chemical_list: D011714:Pyrans; D017640:Silicates; D013343:Styrenes; D015060:1,2-Dipalmitoylphosphatidylcholine; C082825:4-(dicyanomethylene)-2-methyl-6-(4-(dimethylamino)styryl)-4H-pyran; C005691:sodium silicate