ANALYSIS OF STATIC AND DYNAMIC HOST-GUEST ASSOCIATIONS OF DETERGENTS WITH CYCLODEXTRINS VIA PHOTO-LUMINESCENCE METHODS
ANALYSIS OF STATIC AND DYNAMIC HOST-GUEST ASSOCIATIONS OF DETERGENTS WITH CYCLODEXTRINS VIA PHOTO-LUMINESCENCE METHODS
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DOI：
10.1021/ja00371a001
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发表时间：
1982-01-01
影响因子：
15
通讯作者：
CHUNG, CJ
中科院分区：
文献类型：
--
作者：
TURRO, NJ;OKUBO, T;CHUNG, CJ
本文报道了一系列阳离子磷光洗涤剂探针（即[n-（4-溴萘甲酰基）烷基]三甲基溴化铵，烷基=甲基（= 1，BNK-1+），戊基（= 5，BNK-5+）和癸基（= 10，BNK-10+））与环糊精（CD）之间的主客体包结型缔合作用。未检测到与CD相关的证据。缔合平衡常数（AT）、缔合速率常数（kf）和解离速率常数（kb）通过使用Co（NH3）63+作为水相磷光猝灭剂的动态磷光衰减方法来评估。kt值约为107 M-1 s-1，与洗涤剂结构无关。然而，kb和K的大小作为洗涤剂和主体结构的函数在几个数量级上变化。环糊精（CD's）具有疏水空腔，在水溶液中可以包合多种化合物，其性质可以从疏水性到离子性变化。2了解这些关联的机制可能有助于理解酶和相关动力学。尽管进入环糊精空腔的包合过程的入口/出口动力学的重要性，相对较少的数据上的关联（KF）和解离（KB）的速率常数已被报道。用于获得这种动力学数据的方法通常涉及温度跃变和超声弛豫方法。3发光探针非常适合于这种动力学分析，因为包含在CD腔中的发光探针阿普可以在其发光强度、光谱分布和衰减时间方面经历特征变化。3a '4这些变化，以及对包含物时发光的动态猝灭的测量，特别是当这种猝灭
Host-guest inclusion type associations between ß-and-cyclodextrins (CD) and a series of cationic phosphorescence detergent probes (ie,[n-(4-bromonaphthoyl) alkyl] trimethylammonium bromide, alkyl= methyl (= 1, BNK-1+), pentyl (= 5, BNK-5+), and decyl (= 10, BNK-10+)) are reported. No evidence for association could be detected for-CD. The association equilibrium constant (AT), the association rate constant (kf), and the dissociation rate constant (kb) were evaluated from a dynamic phosphorescence decay method by using Co (NH3) 63+ as an aqueous-phase phosphorescence quencher. The kt values are of the order of 107 M" 1 s_1 and are independent of the detergent structure. However, the magnitudes of kb and K vary over several orders of magnitude as a function of detergentand host structure. The results are discussed in terms of the importanceof the dehydrationof CD and/or probe as a rate-determining step of inclusion.Cyclodextrins (CD’s) possess hydrophobic cavities that are able to include, in aqueous solution, a variety of compounds whose character may vary from hydrophobic to ionic. 2 Knowledge of the mechanism of these associations is potentially of assistance for an understanding of enzyme and related kinetics. In spite of the importance of entrance/exit kinetics of the inclusion process into a cyclodextrin cavity, relatively few data on the rate constants for association (kf) and dissociation (kb) have been reported. The methods employed to obtain such kinetic data usually have involved temperature jump and ultrasonic relaxation methods. 3 Luminescence probes are very conveniently suited for such kinetic analysis because luminescence probes which arp included in the cavity of a CD may undergo characteristic changes in their lu-minescence intensity, spectral distribution, and decay time. 3a’4 These changes, as well as measurements of dynamic quenching of luminescence upon inclusion, especially when such quenching