CH CONH Research Articles

Ultrafast dynamics in aqueous polyacrylamide solutions.

We have investigated the ultrafast dynamics of aqueous polyacrylamide ([-CH(2)CH(CONH(2))-](n), or PAAm) solutions using femtosecond optical heterodyne-detected Raman-induced Kerr effect spectroscopy (OHD-RIKES). The observed aqueous PAAm dynamics are nearly identical for both M(w) = 1500 and 10 000. Aqueous propionamide (CH(3)CH(2)CONH(2), or PrAm) solutions were also studied, because PrAm is an exact model for the PAAm constitutional repeat unit (CRU). The longest time scale dynamics observed for both aqueous PAAm and PrAm solutions occur in the 4-10 ps range. Over the range of concentrations from 0 to 40 wt %, the picosecond reorientation time constants for the aqueous PAAm and PrAm solutions scale linearly with the solution concentration, despite the fact that the solution shear viscosities vary exponentially from 1 to 264 cP. For a given value of solution concentration in weight percent, constant ratios of measured reorientation time constants for PAAm to PrAm are obtained. This ratio of PAAm to PrAm reorientation time constants is equal to the ratio of the volume for the PAAm constitutional repeat unit (-CH(2)CHCONH(2)-) to the molecular volume of PrAm. For these reasons, we assign the polymer reorientation dynamics to motions of the entire constitutional repeat unit, not only side group motions. Simple molecular dynamics simulations of H[-CH(2)CH(CONH(2))-](7)H in a periodic box with 180 water molecules support this assignment. Amide-amide and amide-water hydrogen-bonding interactions lead to strongly oscillatory femtosecond dynamics in the Kerr transients, peaking at 80, 410, and 750 fs.

Preparation and characterization of the complexes Cu(PTU) 2Cl, Cu(ETU) 2Cl and Cu(BTU) 2Cl (PTU: R=phenyl, ETU: R=ethyl, BTU: R=benzyl in CH 3CH=CHCONHCSNHR); crystal structure of the Cu(PTU) 2Cl complex

The complexes Cu(PTU) 2Cl, Cu(ETU) 2Cl and Cu(BTU) 2Cl (PTU: R=phenyl, ETU: R=ethyl, BTU: R=benzyl in CH 3CHCHCONHCSNHR) were prepared by the reaction of CuCl 2 with the corresponding derivates of 2-propenoyl thiourea. The complexes were investigated by the methods of CHN analysis, infrared spectroscopy, 1H and· 13C NMR spectroscopy. The crystal structure of Cu(PTU) 2Cl was determined by X-ray analysis: triclinic space group P 1 , a=15.538(1), b=14.296(2), c=12.016(2) Å, α=102.72(1), β=105.95(1), λ=94.31(1)°, D m=1.44(1), D c=1.44 g cm -3, Z=4, R=0.066. The unit cell of Cu(PTU) 2Cl contains two centrosymmetrical dimer molecules of the complex (denoted as A and B) with a different coordination sphere of the Cu(I) atoms. In molecule A two atoms of Cu(I) with coordination number 4 are bridged through chloride bridges (CuCl 2.318(2) and CuCl′ 2.762(2) Å) and two molecules of PTU are terminally coordinated through the S atoms. In molecule B the bridges are formed by the atoms of S of one PTU molecule (CuS 2.235(2) and CuS′ 2.904(2) Å). The other PTU molecule as well as the Cl − anion are terminally bonded. The results of infrared and NMR spectroscopy indicate that the complexes containing ETU or BTU exhibit analogous structure.

Spermatic toxicity of diazoacetyl-glycine amide (DGA) in mice

Summary Female Swiss albino mice were mated with males previously treated with DGA. Whereas a dose of 500 mg/kg/day for 4. days had no appreciable effect, the treatment of the males with 700 mg/kg/ day for 4 days caused a decrease in the number of litters and newborns. DGA is a derivative of diazoacetyl-glycine, with the following chemical structure: N N CH CO NH CH2 CO NH2 It has a marked antitumour activity on the ascitic forms of Sarcoma 180 and Ehrlich carcinoma and on the Galliera rat sarcoma, and a more limited tumour-inhibiting activity on the solid forms of Sarcoma 180 and Ehrlich carcinoma, and on the Harding-Passey melanoma ( Baldini and Brambilla, 1966 ). It also has a remarkable immunodepressant activity. Treatments with DGA significantly prolong the mean survival time of skin graft in H-2 incompatible mice and are effective in allowing the growth of L1210 Leukemia allgrafts in the C$7BL/6 strain and the development of Ehrlich ascites carcinoma in immunized mice ( Brambilla et al., 1970 ). The diazoacetyl-glycine derivatives have a noteworthy toxic activity on many rapidly growing cells and tissues. When administered to animals, they cause bone hypoplasia, marked lymphocytopenia, damage to the gastric and intestinal epithelium, but fail to inhibit rat liver regeneration ( Brambilla et al., 1969 ). The aim of the present investigation was to examine the possible toxic action of DGA on spermatogenesis, which requires synthesis of proteins and nucleic acids, a potential target for the action of DGA.