Determine the decomposition chemistry of H₂Pc on In₂O₃(111)

Determine the specific chemical mechanism by which H₂Pc decomposes on the In₂O₃(111) surface at moderately elevated temperatures.

Background

The study finds that metal-free phthalocyanine (H₂Pc) begins to fragment on In₂O₃(111) at approximately 50 °C, substantially below the temperature at which CoPc and CuPc remain stable. This behavior suggests that the oxide surface actively participates in decomposition rather than merely failing to stabilize the molecule through a central metal ion.

The authors do not identify the chemical pathway responsible for this surface-induced fragmentation, leaving unresolved which bonds, surface species, or reaction processes control the decomposition.

References

This suggests that the In2O3(111) surface plays an active role in the decomposition, though the specific chemistry involved remains open.

— The absence of a central metal ion destabilizes phthalocyanine on In$_2$O$_3$(111)  (2609.08742 - Waidbacher et al., 8 Sep 2026) in Discussion, paragraph beginning “The absence of the central metal appears directly connected…”

The second route via the metallic In$0$ adatoms produced upon mild surface reduction, while chemically accessible, remains unclear. The reduced surface yields a mixed adsorbate of intact F-configured H$_2$Pc (minority) together with distorted features that do not resemble a Pc molecule any more and thus cannot be identified by imaging alone.

— The absence of a central metal ion destabilizes phthalocyanine on In$_2$O$_3$(111)  (2609.08742 - Waidbacher et al., 8 Sep 2026) in Discussion, paragraph beginning “Beyond this general argument…”