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The structure of the monoprotonated ion, 2, of 5-methyl-1,5,9-triazabicyclo[7.3.1]tridecane, 1, as a picrate shows an NMeH+ group engaged in a transannular hydrogen bond with one of the aminal nitrogen atoms and this, in turn, induces a small but measurable structural anomeric effect in the aminal functional group. Diprotonation of 1 in CF3CO2H yields an equilibrium mixture of two isomeric bicyclic dications which are interconverted via a monocyclic ion containing a H2CN+ group and further protonation by CF3SO3H traps the iminium ion as a monocyclic trication. The structure of the monoprotonated ion, 4, of 1,4,8,11-tetraazatricyclo[9.3.1.14,8]hexadecane, 3, as a perchlorate shows the cation with effective C2 symmetry, a nearly linear, and almost symmetrical, transannular hydrogen bond, and a more pronounced structural anomeric effect in both hexahydropyrimidine units. Diprotonation of 3 gives a dication, 5, and the structure of the bis(trifluoroacetate) shows measurable shortening of the aminal C–NR2 bond in spite of the fact that the lone pair and the C–N+ bond are close to gauche. The structural effects in 2, 4, and 5 are well-reproduced by Becke–Perdew density functional theory calculations, and a natural bond orbital analysis of the parent system H3N–H+· · ·NH2CH2NH2, based on SCF and MP2 ab initio calculations is described.

1,5,9-Triazacyclododecane and related macrocyclic triamines can be conveniently constructed around a single carbon atom as template; this route permits the preparation of selectively alkylated derivatives.

There is a growing interest in the development of wound dressings that possess functionality beyond providing physical protection and an optimal moisture environment for the wound. To this end, a novel dressing material based on a sulfonated triblock polymer has been developed. This versatile polymer possesses an ion-exchange capability that is amenable to binding and controlled release of a variety of therapeutic agents. This sulfonated polymer offers several advantages over existing commercial hydrogels used as wound dressings. These include (1) hydrophilicity that is proportional to sulfonation level, (2) easy preparation of fabric supported dressings (e.g., polyester, cotton, nylon), (3) excellent mechanical integrity of the materials when hydrated, (4) stability to a variety of chemistries, and (5) stability to a variety of sterilization methodologies. In this study, polymer was coated onto a polyester fabric and then modified by ion exchange to prepare the sodium, silver, or doxycycline salts. These sulfonated triblock polymer formulations were then evaluated for their capacity to sequester the neutrophil proteases, elastase, and collagenase-2 (MMP-8). Several of the formulations were found to sequester significant amounts of either elastase or collagenase. These formulations were demonstrated to be tested against a commercially available dressing that is currently marketed for its protease-inhibiting capability. The experimental dressing was statistically superior to the commercial dressing at inhibiting MMP-8 and elastase under the same conditions.

1,5,9-Triazacyclododecane and related macrocyclic triamines can be conveniently constructed around a single carbon atom as template; this route permits the preparation of selectively alkylated derivatives.

We would like to report the synthesis of new third order nonlinear optical materials formed from reaction of dibromothiophenes with p-phenylenediamines under Ullmann condensation conditions. Initial measurements of the third harmonic NLO susceptibilities (X3~= 4 × 10−10 esu ), high laser damage thresholds ( 4 GW/cm2 ), and low absorptions have provided promising materials for device applications. Composite films in poly(vinylalcohol), poly(methylmethacrylate). or poly(carbonate) also gave significant X3 values in less than 10 percent w/w concentrations.

Efficient schemes for selective N-protection of 1,4,7-triazacyclononane and 1,5,9-triazacyclododecane and for synthesis of related bis-coronands are based upon the synthetic intermediacy of tricyclic orthoamides.

Efficient schemes for selective N-protection of 1,4,7-triazacyclononane and 1,5,9-triazacyclododecane and for synthesis of related bis-coronands are based upon the synthetic intermediacy of tricyclic orthoamides.