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arXiv · 2606.30494

Spontaneous Symmetry Breaking and Emergent Helicity in Achiral D4h-Symmetric Zinc Phthalocyanine Condensates

Bruno S. Zanatta·Giovani B. de Oliveira·Marcos E. G. Carmo·Antonio Eduardo H. Machado·Thiago F. Silva·Guilherme F. S. Miguel·Antonio Otavio T. Patrocinio·Raigna A. da Silva·Erick Piovesan·Alexandre Marletta
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Abstract

Herein it is shown spontaneous symmetry breaking in supramolecular aggregates of D4h-symmetric zinc phthalocyanine (ZnPc). Ab initio density functional theory calculations at the M06/DGDZVP level reveal that intermolecular interactions induce a subtle relaxation of the macrocyclic framework, producing a characteristic red shift of the aza-bridge (C-N-C) stretching mode and symmetric stretching of the pyrrole ring. Confocal Raman Optical Activity measurements further reveal a negative Cotton effect at 1505 cm^-1 and 1338 cm^-1, providing evidence of emergent supramolecular chirality. Our findings identify pristine ZnPc as a model system for spontaneous self-assembled chiral symmetry breaking in molecular condensates and suggest new opportunities for chiroptical, spin-selective, and quantum functional materials.

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Bruno S. Zanatta, Giovani B. de Oliveira, Marcos E. G. Carmo, Antonio Eduardo H. Machado, Thiago F. Silva, Guilherme F. S. Miguel, Antonio Otavio T. Patrocinio, Raigna A. da Silva, Erick Piovesan, Alexandre Marletta. 2026-06-29. Spontaneous Symmetry Breaking and Emergent Helicity in Achiral D4h-Symmetric Zinc Phthalocyanine Condensates. https://arxiv.org/abs/2606.30494

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