Sen Pratik, Mukherjee Saptarshi, Patra Amitava, Bhattacharyya Kankan
Physical Chemistry Department, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India.
J Phys Chem B. 2005 Mar 3;109(8):3319-23. doi: 10.1021/jp0455327.
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.
已对包裹于硅酸钠衍生的溶胶 - 凝胶玻璃中的二棕榈酰磷脂酰胆碱（DPPC）囊泡中的4 - （二氰基亚甲基）-2 - 甲基 - 6 - （对二甲氨基苯乙烯基）-4H - 吡喃（DCM）的溶剂化动力学进行了研究。溶胶 - 凝胶玻璃中DPPC的溶剂化动力学由350±50皮秒（50%）和2300±200皮秒（50%）的两个组分描述，总动态斯托克斯位移为1300厘米⁻¹。快速组分（350皮秒）与本体水中DPPC囊泡中的快速组分（320±50皮秒）相似。该组分可能归因于囊泡水池内水分子的动力学。然而，慢速组分（2300±200皮秒）比DCM在本体溶剂中的DPPC囊泡中溶剂化动力学的慢速组分（900±100皮秒）慢约2.5倍。溶胶 - 凝胶玻璃和本体水中DPPC囊泡中DCM的各向异性衰减均呈现出非常快速的初始衰减，且具有较大的残余各向异性，在约10纳秒内不衰减。各向异性衰减的时间尺度与溶剂化动力学的时间尺度非常不同。
