Intercalative insertion

Bay Region B[a]P-Ne-Adenine Adducts (Figure 12.3b) Distorting Intercalative Insertions from the Major Groove... 

Intercalators associate with dsDNA by insertion between the stacked base pairs of DNA [52], EtBr binds to dsDNA with little to no sequence specificity, with one dye molecule inserting for every 4-5 base pairs [53]. It also binds weakly via a non-intercalative binding mechanism only after the intercalative sites have been saturated [54], Propidium iodide (PRO) is structurally similar to ethidium bromide, and both dyes show a fluorescence enhancement of approximately 20-30 fold upon binding to dsDNA [41]. As well, their excitation maxima shift 30-40 nm upon binding due to the environment change associated with intercalation into the more rigid and hydrophobic interior of the double-stranded nucleic acid structure relative to aqueous solution [41]. 

Table I shows examples of the steady-state and time-resolved emission characteristics of [Ru(phen)2(dppz)]2+ upon binding to various DNAs. The time-resolved luminescence of DNA-bound Ru(II) is characterized by a biexponential decay, consistent with the presence of at least two binding modes for the complex (47, 48). Previous photophysical studies conducted with tris(phenanthroline)ruthenium(II) also showed biexponential decays in emission and led to the proposal of two non-covalent binding modes for the complex (i) a surface-bound mode in which the ancillary ligands of the metal complex rest against the minor groove of DNA and (ii) an intercalative stacking mode in which one of the ligands inserts partially between adjacent base pairs in the double helix (36, 37). In contrast, quenching studies using both cationic quenchers such as [Ru(NH3)6]3+ and anionic quenchers such as [Fe(CN)6]4 have indicated that for the dppz complex both binding modes...

Composites have been prepared by rather different methods due to the great variety of inorganic and organic materials used. (See also Sect. 2.5. and Chap. 7) Lamellar nanocomposites consisting of layered inorganic compounds and conducting polymers display novel properties which result from the molecular-level interactions of two dissimilar chemical components. The intercalative polymerization of aniline in an a-RuCL host has recently been reported. The insertion of aniline into a-RuCls has been executed by soaking the a-RuCL crystals in aniline or ani-... 

Three different methods have been used to prepare polymer-clay nanocomposites. In the in situ intercalative polymerization, the first method, a precursor solution (monomer liquid or monomer solution) is inserted into the basal spaces of expanding clay layers, followed... 

A simple binding between small molecules and DNA occurs by the process of intercalation. Intercalative binding involves a noncovalent interaction that results from the insertion of the small molecules between the base pairs of the DNA helix. Intercalation commonly occurs with flat aromatic molecules that are held perpendicular to the axis of the DNA helix. Metal complexes with aromatic ligands can intercalate into DNA. ... 

A demonstrated method to insert polymer chains into host structures is by in-situ intercalative polymerization of a monomer using the host itself as the oxidant. FeOCl is one of the most convenient redox-intercalation hosts for a great variety of molecules including conducting polymers. The in-situ intercalative polymerization of pyrrole, 2,2 -bithiophene and aniline in the interlayer space of this material has been reported. The resulting intercalation compounds are composed... 

---