English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

5,7-Di(4-tert-butylphenyl)-6H-1,4-diazepine-2,3-dicarbonitrile, prepared by condensation of di(4-tert-butyl benzoyl) methane with diaminomaleodinitrile, affords upon template cyclotetramerization in the presence of magnesium(II) butoxide in n-butanol the Mg II complex of octa-4-tert-butylphenyl substituted tetra(1,4-diazepino) porphyrazine. The strong solvent effect on its UV-Vis and 1 H NMR spectral properties is rationalized in terms of dimerization occurring very likely due to intermolecular hydrogen bonding between diazepine nitrogen atoms and water molecules. The monomer is present exclusively only in diluted solutions of aprotic solvents such as dimethyl sulfoxide and dimethylformamide. Addition of water or methanol leads to dimerization. The dimer exists also in pyridine and tetrahydrofuran solutions, as well in benzene and dichloromethane containing residual water or alcohol. The UV-Vis spectrum of the monomer is typical for Mg II porphyrazines and contains a single Q band at ca. 680 nm. In its 1 H NMR spectrum the resonance of the CH 2 protons is not observed at ambient temperatures but appear as a broad signal at 4.4-4.5 ppm above 100 o C, which is characteristic for rapid inversion of the 1,4-diazepine ring in the 6H form. The Q band of the dimer is split into two components (major at 640-645 nm and minor at 680-685 nm). The dimer gives two doublets of the diastereotopic CH 2 protons (5.9-7.1 ppm for the equatorial and 4.8-6.1 ppm for the axial CH 2 protons, depending on the solvent) with characteristic geminal splitting of ca. 11-12 Hz. Formation of the dimer hinders the inversion of diazepine rings and two sharp doublets are observed even above 100 o C.

makrogeterocikly

Porphyrazines with Annulated Diazepine Rings. 3. Mg(II) Complex of 4-tert-Butylphenyl Substituted Tetra(1,4-diazepino)porphyrazine: Synthesis and Peculiar Effect of Solvent on Its Spectral Properties