Skip to content
DraconiticResearch
Search Sources API
178,033 studies31 sourcesUpdated 32 min ago
Peer-reviewedCC BY 4.0Inorganics

Nickel Complexes as Artificial Urea Lyases with 1012-Fold Rate Enhancement

  • Letícia K. Sebastiany1
  • Gabrielle R. Conciani1
  • Rafael G. Silveira2
  • Rafael S. Freitas3
  • Caterina G. C. Marques Netto1,4
4 affiliations
  1. 1Departamento de Química, Universidade Federal de São Carlos, Rodovia Washington Luís, Km 235 s/n, São Carlos 13565-905, SP, Brazil
  2. 2Instituto Federal Goiano, Campus CERES, Ceres 76300-000, GO, Brazil
  3. 3Instituto de Física, Universidade de São Paulo, São Paulo 05314-970, SP, Brazil
  4. 4Department of Biochemistry, School of Medicine, Emory University, 1510 Clifton Rd NE, Atlanta, GA 30329, USA
Open at sourceDOICite

Abstract

Catalytic acceleration of urea decomposition offers a route to artificial urea lyases. Because urease-inspired complexes do not reproduce the enzymatic hydrolysis pathway but instead promote urea decomposition, we developed four dinuclear nickel catalysts for urea lyase activity. The complexes are phenolate-bridged in the solid state, with triazole units bearing butyl ((Ni,Ni)L1), n-propanol ((Ni,Ni)L2), or phenyl ((Ni,Ni)L3 and (Ni,Ni)L3″) groups at C4 to modulate the electronic and secondary coordination environment. Characterization by microanalysis, MALDI-TOF, FTIR, UV-Vis, 1H NMR, TGA, conductivity, and magnetic susceptibility indicates high-spin Ni(II) centers in (Ni,Ni)L1-L3 and a nearly diamagnetic species in (Ni,Ni)L3″. All complexes catalyzed urea decomposition to isocyanate and ammonia. Stopped-flow pH monitoring showed that (Ni,Ni)L1 and (Ni,Ni)L3 complexes gave the greatest rate enhancements (kcat/knon-cat = 7.7 × 1011 for (Ni,Ni)L1 and 4.6 × 1012 for (Ni,Ni)L3). These differences were linked to distinct active species in solution in which aquation breaks the phenolate bridge and generates species with different electrolyte compositions. The most active complexes formed 2:1 electrolytes, whereas the less active ones formed 1:1 or 3:1 electrolytes. These results relate solution-state speciation to urea lyase activity and highlight the role of coordination-sphere reorganization in controlling catalytic urea decomposition.

Related

  1. General Preparation of Nickel-Based Compound/Carbon Nanotube Catalysts for the Urea Oxidation Reaction
    Yanjie Xia, Sheng-Zhi Ma, Yi-Jun Chen +4
    Nanomaterials (Basel, Switzerland)Peer-reviewedCC BYFull textElectrochemistry & energyEurope PMCCrossref
  2. Ni0.85Se Nanosheet Arrays on Nickel Foam as a Robust Non-Noble Metal Electrocatalyst for Energy-Efficient Urea Oxidation
    John Anthuvan Rajesh, Shrine Maria Nithya Jeghan, Soon-Hyung Kang +1
    NanomaterialsPeer-reviewedCC BY 4.0Electrochemistry & energyCrossref
  3. Mechanistic Understanding of Nickel Catalyzed Urea Oxidation Reaction to Cyanate and Nitrite
    Kyu In Shim, Jiseon Kim, Miyeon Kim +2
    ExplorationPeer-reviewedCC BY 4.0Full text2 citedElectrochemistry & energyPMC
  4. Understanding the steric demand of the reactions of nickel(0) complexes with aryl halide substrates
    Risnita Vicky Listyarini, Ryan Oliver, Hio U. Lao +1
    ChemRxivPreprintCC BYFull textOrganic chemistryChemRxiv
  5. Air-Stable Nickel(0) Complexes with Room-Temperature Photoluminescence.
    Tim H Eggenweiler, Oliver S Wenger
    JACS AuPeer-reviewedCC BY-NC-NDFull textPhysical chemistryEurope PMCPMC

Cite

BibTeXRIS
BibTeX
@article{sebastiany2026nickel,
  title = {{Nickel Complexes as Artificial Urea Lyases with 1012-Fold Rate Enhancement}},
  author = {Letícia K. Sebastiany and Gabrielle R. Conciani and Rafael G. Silveira and Rafael S. Freitas and Caterina G. C. Marques Netto},
  journal = {Inorganics},
  year = {2026},
  month = oct,
  doi = {10.3390/inorganics14110277},
  url = {https://www.mdpi.com/2304-6740/14/11/277},
  note = {CC BY 4.0},
}
RIS
TY  - JOUR
TI  - Nickel Complexes as Artificial Urea Lyases with 1012-Fold Rate Enhancement
AU  - Letícia K. Sebastiany
AU  - Gabrielle R. Conciani
AU  - Rafael G. Silveira
AU  - Rafael S. Freitas
AU  - Caterina G. C. Marques Netto
PY  - 2026
DA  - 2026/10/29
JO  - Inorganics
DO  - 10.3390/inorganics14110277
UR  - https://www.mdpi.com/2304-6740/14/11/277
AB  - Catalytic acceleration of urea decomposition offers a route to artificial urea lyases. Because urease-inspired complexes do not reproduce the enzymatic hydrolysis pathway but instead promote urea decomposition, we developed four dinuclear nickel catalysts for urea lyase activity. The complexes are phenolate-bridged in the solid state, with triazole units bearing butyl ((Ni,Ni)L1), n-propanol ((Ni,Ni)L2), or phenyl ((Ni,Ni)L3 and (Ni,Ni)L3″) groups at C4 to modulate the electronic and secondary coordination environment. Characterization by microanalysis, MALDI-TOF, FTIR, UV-Vis, 1H NMR, TGA, conductivity, and magnetic susceptibility indicates high-spin Ni(II) centers in (Ni,Ni)L1-L3 and a nearly diamagnetic species in (Ni,Ni)L3″. All complexes catalyzed urea decomposition to isocyanate and ammonia. Stopped-flow pH monitoring showed that (Ni,Ni)L1 and (Ni,Ni)L3 complexes gave the greatest rate enhancements (kcat/knon-cat = 7.7 × 1011 for (Ni,Ni)L1 and 4.6 × 1012 for (Ni,Ni)L3). These differences were linked to distinct active species in solution in which aquation breaks the phenolate bridge and generates species with different electrolyte compositions. The most active complexes formed 2:1 electrolytes, whereas the less active ones formed 1:1 or 3:1 electrolytes. These results relate solution-state speciation to urea lyase activity and highlight the role of coordination-sphere reorganization in controlling catalytic urea decomposition.
SN  - 2304-6740
ER  -