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Impact of the anion and chalcogen on the crystal structure and properties of 4,6‐dimethyl‐2‐pyrimido(thio)nium halides
Author(s) -
Okuniewski Andrzej,
Rosiak Damian,
Chojnacki Jarosław
Publication year - 2020
Publication title -
acta crystallographica section c
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 17
ISSN - 2053-2296
DOI - 10.1107/s2053229620005525
Subject(s) - iodide , chemistry , thiourea , bromide , halide , medicinal chemistry , thio , urea , chloride , crystal structure , inorganic chemistry , organic chemistry
By the reaction of urea or thiourea, acetylacetone and hydrogen halide (HF, HBr or HI), we have obtained seven new 4,6‐dimethyl‐2‐pyrimido(thio)nium salts, which were characterized by single‐crystal X‐ray diffraction, namely, 4,6‐dimethyl‐2‐oxo‐2,3‐dihydropyrimidin‐1‐ium bifluoride, C 6 H 9 N 2 O + ·HF 2 − or (dmpH)F 2 H, 4,6‐dimethyl‐2‐oxo‐2,3‐dihydropyrimidin‐1‐ium bromide, C 6 H 9 N 2 O + ·Br − or (dmpH)Br, 4,6‐dimethyl‐2‐oxo‐2,3‐dihydropyrimidin‐1‐ium iodide, C 6 H 9 N 2 O + ·I − or (dmpH)I, 4,6‐dimethyl‐2‐oxo‐2,3‐dihydropyrimidin‐1‐ium iodide–urea (1/1), C 6 H 9 N 2 O + ·I − ·CH 4 N 2 O or (dmpH)I·ur, 4,6‐dimethyl‐2‐sulfanylidene‐2,3‐dihydropyrimidin‐1‐ium bifluoride–thiourea (1/1), C 6 H 9 N 2 S + ·HF 2 − ·CH 4 N 2 S or (dmptH)F 2 H·tu, 4,6‐dimethyl‐2‐sulfanylidene‐2,3‐dihydropyrimidin‐1‐ium bromide, C 6 H 9 N 2 S + ·Br − or (dmptH)Br, and 4,6‐dimethyl‐2‐sulfanylidene‐2,3‐dihydropyrimidin‐1‐ium iodide, C 6 H 9 N 2 S + ·I − or (dmptH)I. Three HCl derivatives were described previously in the literature, namely, 4,6‐dimethyl‐2‐oxo‐2,3‐dihydropyrimidin‐1‐ium chloride, (dmpH)Cl, 4,6‐dimethyl‐2‐sulfanylidene‐2,3‐dihydropyrimidin‐1‐ium chloride monohydrate, (dmptH)Cl·H 2 O, and 4,6‐dimethyl‐2‐sulfanylidene‐2,3‐dihydropyrimidin‐1‐ium chloride–thiourea (1/1), (dmptH)Cl·tu. Structural analysis shows that in 9 out of 10 of these compounds, the ions form one‐dimensional chains or ribbons stabilized by hydrogen bonds. Only in one compound are parallel planes present. In all the structures, there are charge‐assisted N + —H… X − hydrogen bonds, as well as weaker C Ar + —H… X − and π + … X − interactions. The structures can be divided into five types according to their hydrogen‐bond patterns. All the compounds undergo thermal decomposition at relatively high temperatures (150–300 °C) without melting. Four oxopyrimidinium salts containing a π + … X − …π + sandwich‐like structural motif exhibit luminescent properties.