Synthesis and structural investigation of brightly colored organoammonium 1,3-dimethylviolurates

Volker Lorenz; Phil Köhler; Lea Schröder; Liane Hilfert; Rüdiger Goldhahn; Frank T. Edelmann

doi:10.1515/znb-2025-0049

Article

Synthesis and structural investigation of brightly colored organoammonium 1,3-dimethylviolurates

Volker Lorenz , Phil Köhler , Lea Schröder , Liane Hilfert , Rüdiger Goldhahn and Frank T. Edelmann

Published/Copyright: September 12, 2025

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From the journal Zeitschrift für Naturforschung B Volume 80 Issue 9-10

Abstract

Seven new organoammonium 1,3-dimethylviolurates [R¹R²R³NH][1,3-Me₂Vio] R¹ = R² = H, R³ = ^tBu (3), R³ = Cy (cyclohexyl) (4), R³ = Ad (adamantyl) (5), R³ = C₆H₂Me₂-4,5-NH₂-2 (6); R¹ = H, R² = R³ = Et (7), ⁱPr (8); R¹ = H, R² + R³ = (–CH₂–)₄ (9) have been prepared by treatment of 1,3-dimethylvioluric acid (2, = HMe₂Vio) with different primary and secondary amines. All violurate salts form bright blue or red/purple, nicely crystalline solids. The compounds have been characterized by their solid-state IR and solution NMR (¹H, ¹³C) and UV-spectroscopic data as well as elemental analyses. Structure determinations by single-crystal X-ray diffraction of compounds 4, 7 and 9 revealed supramolecular self-assembly into different one-dimensional substructures through cation–anion N–H⋯N and N–H⋯O hydrogen bonds. In addition, the molecular and crystal structure of anhydrous 1,3-dimethylvioluric acid (2) has also been determined.

Keywords: 1,3-dimethylvioluric acid; 1,3-dimethylviolurates; organoammonium; hydrogen bonds; crystal structure

Corresponding author: Frank T. Edelmann, Institut für Physik, Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany, E-mail: frank.edelmann@ovgu.de

Dedicated to Professor Herbert W. Roesky on the Occasion of his 90th Birthday.

Research ethics: Not applicable.
Informed consent: Not applicable.
Author contributions: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission. The syntheses were performed by VL and LS. FTE conceived and supervised the research work and wrote the original manuscript. PK carried out the single-crystal X-ray analyses and wrote the respective part of the manuscript. LH measured and interpreted all spectra. RG provided the necessary infrastructure.
Use of Large Language Models, AI and Machine Learning Tools: None declared.
Conflict of interest: The authors declare no conflict of interest.
Research funding: General financial support of this work by the Otto-von-Guericke-Universität Magdeburg is gratefully acknowledged.
Data availability: The raw data can be obtained on well-founded request from the corresponding author.

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Received: 2025-07-14

Accepted: 2025-07-24

Published Online: 2025-09-12

Published in Print: 2025-10-27

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https://doi.org/10.1515/znb-2025-0049

Keywords for this article

1,3-dimethylvioluric acid; 1,3-dimethylviolurates; organoammonium; hydrogen bonds; crystal structure