Carbon paste electrode was modified by disodium 2,4-diamino-7-methylbenzo[g] pteridine-5,10-dioxide to fabricate a sensor for potentiometric determination of vanadyl ion (VO2+) in aqueous medium. The new ligand was synthesized in three steps with high yield. The optimal composition of the carbon paste was made of graphite powder (64.5%), ionophore (16.6%), paraffin oil (17.8%), a...

Abstract A sulfonic acid-functionalized trimethyl-substituted polyimide was synthesized by reacting 4,4?-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and 3,5-diamino-2,4,6-trimethylbenzenesulfonic acid (TrMSA). The properties of 6FDA-TrMSA were compared to the related 6FDA-derived analogues made from 2,4,6-trimethylbenzene-1,3-diamine (6FDA-TrMPD) 3,5-diamino-2,4,6-trimethylbenzene ben...

The autocatalytic system, N-phospho-a-amino acids, could not only self-assemble into oligo-peptides but also act as the phosphorylation reagents to phosphorylate the nucleosides into nucleotides and oligo-nucleotides, in aqueous medium. While, the b-amino acids did not have such properties.

WR99210 but does not affect the intrinsic activity of proguanil. Proc. Natl. Acad. Sci. U. S. A. 94, 10931–10936 30 Walter, R. etal. (1991) Pyrimethamine-resistantPlasmodiumfalciparum lack cross-resistance to methotrexate and 2,4-diamino-5-(substituted benzyl) pyrimidines. Parasitol. Res. 77, 346–350 31 Cunningham, R.F. et al. (1981) Clinical pharmacokinetics of probenecid. Clin. Pharmacokinet....

The asymetric unit of the title salt, 3CH(5)N(2)S(+)·3Cl(-)·2CH(4)N(2)S, contains two mol-ecules of thio-urea, three (diamino-methyl-idene)sulfonium cations and three chloride anions. The crystal packing is stabilized by N-H⋯Cl, N-H⋯S, S-H⋯Cl and S-H⋯S hydrogen bonds, forming a three-dimensional network.

The title compound, C(4)H(8)N(5) (+)·C(2)HO(4) (-), was obtained from the reaction of oxalic acid and 2,4-diamino-6-methyl-1,3,5-triazine. The protonated triazine ring is essentially planar with a maximum deviation of 0.035 (1) Å, but the hydrogen oxalate anion is less planar, with a maximum deviation of 0.131 (1) Å for both carbonyl O atoms. In the crystal, the ions are linked by inter-molecul...

In the title compound, C(4)H(8)N(5) (+)·Cl(-), a two-dimensional layer packing network is observed in which every chloride anion links three adjacent 2,4-diamino-6-methyl-1,3,5-triazin-1-ium cations by N-H⋯Cl hydrogen-bonding inter-actions, forming 12-membered and eight-membered hydrogen-bonded rings with graph-set motifs R(4) (4)(12) and R(3) (3)(8), respectively. In addition, N-H⋯N hydrogen b...

In the title salt, 2C(5)H(8)N(3) (+)·C(4)H(4)O(4) (2-)·3H(2)O, the asymmetric unit contains a protonated 2,3-diamino-pyridinium cation, half of a succinate dianion (disposed about a centre of inversion), and one and a half water mol-ecules. One of the water mol-ecules is disordered over two sites with occupancies of 0.670 (17) and 0.330 (17). The other water mol-ecule has an occupancy of 0.5 (f...

The title compound, C(12)H(17)N(5)O, was obtained by cyclo-condensation of 2,4-diamino-pyrimidine-5-carbonitrile with cyclo-hepta-none. The tetra-hydro-pyrimidine ring has a dis-torted boat conformation and the cyclo-heptane ring adopts a chair conformation. In the crystal, molecules are linked via N-H⋯O and N-H⋯N hydrogen bonds generating a three-dimensional network.