Classical hydrogen bonding and weaker C–H⋯O interactions in complexes of uracil-5-carboxylic acid with the alkali metals Na–Cs

Efficiencies of Super-Plasticizer on Rheology Properties of Fly Ash-Based Alkali-Activated Materials with Different Ms Waterglass Activators

This study investigates the effects of five different super-plasticizers (SPs): melamine sulfonate (M), naphthalene-based (N), lignosulfonate (L), polyether-type (P-I), and polyester-type polycarboxylate super-plasticizers (P-II), on fly ash through fluidity, viscoelasticity, inter-microstructure, and mechanism of action (adsorption and zeta) experiments. Additionally, the stability of SPs on AAs was investigated in the ATR-FTIR experiment. The results show that most SPs were effective admixtures under high Ms (2.25) of waterglass (WG) alkali activators (AAs), while P-I SPs performed better under low Ms (1.0) of WG AAs in FA-AAM fly ash pastes. Meanwhile, the higher adsorption and zeta values of samples with P-I SPs were useful for the increase of mesh size of inter-particles and consequently promoted the rheology of FA-AAMs fresh pastes. The more stable structure (ether bond) and the formation of small functional groups (carboxylic acid groups) of P-I SPs in the AAs environment may be the main reasons for this.

A mixed molecular salt of lithium and sodium breaks the Hume-Rothery rules for solid solutions

Despite the difference in size and chemistry, lithium and sodium form a solid solution as isoorotate salt. Such behaviour, which represents an exception to the Hume-Rothery rules, can be exploited in the preparation of novel lithium drugs.

An insight into the photophysical properties of amide hydrogen bonded N-(benzo[d]thiazol-2-yl) acetamide crystals

Three distinct, hydrogen bond associated N-(benzo[d]thiazol-2-yl) acetamides were synthesized by refluxing benzothiazoles with acetic acid. The nature of the assemblies was characteristic to the substituent in the benzothiazole moiety. In N-(benzo[d]thiazol-2-yl)acetamide, water acts as a bridge for forming three hydrogen bonds, as an acceptor to amide NH, and donors to carbonyl of amide and thiazole nitrogen assembles of three different N-(benzo[d]thiazol-2-yl)acetamide molecules. The N-(6-methylbenzo[d]thiazol-2-yl)acetamide formed a (amide) N-H…N (thiazole) bonded R²₂(8) molecular dimers by two homo-intermolecular hydrogen bonding interactions. N-(6-methoxybenzo[d]thiazol-2-yl)acetamide formed (amide)N-H…O (acid) & (acid)O-H…N (thiazole) interactions with the acetic acid, forming a R²₂(8) hydrogen-bonded ring by two hetero-intermolecular hydrogen bonding interactions.

N-(4-Hydroxyphenyl)acetamide against diiodine towards polyiodide dianion

N-(4-Hydroxyphenyl)acetamide decreases the total amount of diiodine which is available for the iodination of tyrosil residues of thyroglobulin, while it inhibits the activity of thyroid peroxidase.