Amines, particularly polyamines, catalyzed the polycondensation of silicic acid in water. The resultant gel contained these polyamines with a N/Si molar ratio of up to 0.5. IR and powder X-ray studies showed that silica gel and polyamines are hybridized at a molecular level through hydrogen bonding. The gel adsorbed anionic dyes from water, whereas normal silica gel adsorbs cationic dyes. Induced CD was observed for the indigo carmine adsorbed on silica gel–poly(l-lysine) hybrid, showing that the hybrid provides a chiral environment to the adsorbate.

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High resolution resonance Raman spectra of octaethylporphyrinato-Ni(II) [Ni (OEP)], its meso-deuterated and 15N substituted derivatives were measured. With excitation near the O–1 transition, about 90 nonfundamental modes and previously unrecognized fundamental modes were observed for each derivative. The analysis of the nonfundamental Raman lines allowed the determination of all the fundamental frequencies in the A1g, B1g, A2g, and B2g species of D4h symmetry. Experimental classification of depolarized Raman lines to the B1g and B2g species was worked out. Combinations of B1g and B2g modes give rise to anomalously-polarized Raman lines while combinations of B1g modes and of B2g modes give rise to polarized lines. The Raman lines of the B1g species of Ni(OEP) with D4h symmetry are correlated with those in the Ag species of H2(OEP) with D2h symmetry while the B2g species of D4h is correlated with the B1g species of D2h. The experimental frequencies of fundamental modes thus determined satisfied the product rule for the isotopic substitution.

Peroxidase activity of a myoglobin reconstituted with a chemically modified heme 1 is reported. The heme 1 bearing a total of eight carboxylates bound to the terminal of propionate side chains is incorporated into apomyoglobin from horse heart to obtain a new reconstituted myoglobin, rMb(1), with a unique binding domain structure. The UV−vis, CD, and NMR spectra of rMb(1) are comparable with those of native myoglobin, nMb. The mixing of rMb(1) with hydrogen peroxide yields a peroxidase compound II-like species, rMb(1)-II, since the spectrum of rMb(1)-II is identical with that observed for nMb. Stoichiometric oxidation of several small molecules by rMb(1)-II, demonstrates the significant reactivity. (i) The oxidation of cationic substrate such as [Ru(NH3)6]2+ by rMb(1)-II is faster than that observed for oxoferryl species of nMb, nMb-II. (ii) Anionic substrates such as ferrocyanide are unsuitable for the oxidation by rMb(1)-II. (iii) Oxidations of catechol, hydroquinone, and guaiacol are dramatically enhanced by rMb(1)-II (14−32-fold) compared to those observed for nMb-II. Thus, the chemical modification of heme-propionates can alter substrate specificity. Steady-state kinetic measurements indicate that both the reactivity and substrate affinity toward guaiacol oxidation by rMb(1) are improved, so that the specificity, k cat/K m, is 13-fold higher than that in nMb. This result strongly suggests that the artificially modified heme-propionates may increase the accessibility of neutral aromatic substrates to the heme active site. The present work demonstrates that the chemical mutation of prosthetic group is a new strategy to create proteins with engineered function.