On the structures, spin states, and optical properties of titanium, platinum, and iron azacalixphyrins: a DFT study

MixedN-aryl/alkyl substitution favours an unusual tautomer of near-infrared absorbing azacalixphyrins

This work depicts the synthesis of a new azacalixphyrin presenting both aryl and alkyl substituents. The joint experimental and theoretical study supports that the substitution pattern favour an unusual 5–7 tautomer.

Fused bis-azacalixphyrin that reaches NIR-II absorptions

The fusion of two azacalixphyrins produces a new class of NIR-II dyes showing an intense absorption band in the 1000–1200 nm NIR range.

Central substitution of azacalixphyrins: a strategy towards acidochromic NIR dyes

A new substitution pattern of azacalixphyrins is proposed and assessed with theoretical tools.