Work

Precise engineering of highly stable titanium-oxo clusters: From synergistic co-assembly to electrochemical detection

Year: 2025

Type: article

Abstract: Primitive reaction synergy is an effective strategy to construct complex assemblies, but the exploration is still in its infancy. Here, we report an organic-inorganic co-assembly method involving controlled dehydration condensation between boric acid and pyrazole which enables the precise synthesis of five titanium-oxo clusters (TOCs) with two distinct titanium-oxo cores. The parallelepiped Ti8O8 core which constructed from the mono-dehydration product (H2R1Bpz2O) with multiple μ3-O bridges exhibited enhanced structural stability and induced conformational distortion for open metal site exposure. Crucially, the tetrahedral Ti4O6 core which was capped with C3v-symmetric pyrazolylborate ligands (HR2Bpz3) via the first-reported in situ bis-dehydration exhibited unprecedented acid/base stability (pH tolerance: -0.778–15.079), surpassing all prior TOCs. Mechanistic studies, supported by stepwise balanced chemical equations, reveal water’s dual role in pyrazolylborate formation: mediating dehydration condensation and cluster nucleation, thus bridging organic-inorganic co-assembly. As a biosensor, 2,4-2FTi8@rGO/GCE electrode delivers benchmark electrochemical performance for chlorogenic acid (CGA), featuring ultrahigh sensitivity (9.486 μA μM-1), nanomolar detection limit (6.59 nM) and a wide linear range (0.1–140 μM). It represents one of the few examples that simultaneously integrates all these key performance advantages. Theoretical calculations indicate that the stronger adsorption of 2,4-2FTi8 toward reaction species leads to its better electrochemical detection performance than MeBTi4. This work establishes a synthetic paradigm for TOCs via organic-inorganic co-assembly and highlights their electrochemical sensing potential.

Source: Nano Research

DOI: 10.26599/nr.2025.94908235