@misc{10481/108864,
year = {2025},
month = {8},
url = {https://hdl.handle.net/10481/108864},
abstract = {Synthesis, characterization, and electrocatalytic water oxidation studies of the cubane-type complexes
[(µ3
-L1
O)CoCl(MeOH)]4 (1) and [(µ3
-L2
O)CoCl(MeOH)]4 (2) are herein reported. Cubanes 1 and 2 were
obtained in high yields under mild conditions by self-assembly of the ligands L1
OH = 1-H-2-benzimidazolylmethanol and L2
OH = 1-methyl-2-benzimidazolylmethanol with CoCl2·6H2O in basic methanolic
solution. Both compounds feature a cubane-type structure in which the central {Co4O4} units are built by
four CoII centers coordinated by alkoxide-bridged oxygen and nitrogen atoms from the deprotonated
Ln
OH ligands and stabilized by MeOH molecules and chloride ions. Magnetic studies allowed the determination of g = 2.42 and g = 2.57 values for 1 and 2, respectively. At low temperatures, 1 shows antiferromagnetic behavior, while 2 shows ferromagnetic coupling. DFT analyses support the antiferromagnetic
behavior of 1. Unfortunately, the same method was not effective at explaining the ferromagnetic character
of 2. Such inconsistency was explained through an exhaustive ac-susceptibility study by considering the
single molecular magnet (SMM) behavior of 2. Cyclic voltammetry of 1 and 2 in phosphate buffer solution
(pH = 7.4) displayed catalytic currents at 1.65 and 1.68 V vs. Standard Hydrogen Electrode (SHE), corresponding to water oxidation, with TOF values of 1.04 and 1.99 s−1
, overpotentials of 710 and 680 mV, faradaic efficiencies of 88% and 90%, and TON values of 2.8 and 3.5 for 1 and 2, respectively.
Electrochemical Quartz Microbalance (EQCM) analysis showed the robustness of 1 and 2 since only
around 0.05% of their mass was deposited on the electrode surface. Subsequent SEM-EDX microanalysis
demonstrated that although 1 converts to CoOx during electrolysis, it also changes into an undetermined
form of the original catalyst, containing C, O, and Co. In the case of 2, analysis of the electrode after
WOC did not allow the detection of Co, C, or O, establishing 2 as a more stable catalyst than 1.},
organization = {CONAHCyT (Beca 695554, Proyecto A1-S-8286)},
organization = {DGAPA-PAPIIT (IN216823)},
organization = {IR INFRANALYTICS FR2054 - French National Research Agency (CUBISM, grant no. ANR-18 CE092 0040 01)},
publisher = {Royal Society of Chemistry},
title = {Electrocatalytic water oxidation with bioinspired cubane-type CoII complexes},
doi = {10.1039/D5DT01000D},
author = {Favela-Mendoza, Roberto and Rul-Ramírez, Elizabeth and García-Alvarez, Ana Cristina and Sánchez Lara, Eduardo and Gamboa-Ramírez, Stefani and Flores Alamo, Marcos and Bertaina, Sylvain and Orio, Maylis and Guerra Tschuschke, Isabel and Castillo, Ivan},
}