A Co-Crystallised Cobalt(II) Cluster of Pyridinedicarboxylic Acid (PDC) as a Luminescent Material for Selective Sensing of Methanol

Victoria T Olayemi; Adedibu C Tella; Folahan A Adekola; Hadley S Clayton; Adetola C Oladipo; Gift Mehlana; Adeniyi S Ogunlaja; Oluwatobi S Oluwafemi; Joseph O Ogar; Stephen P Argent; Robert Mokaya

doi:10.1007/s10895-021-02746-9

A Co-Crystallised Cobalt(II) Cluster of Pyridinedicarboxylic Acid (PDC) as a Luminescent Material for Selective Sensing of Methanol

J Fluoresc. 2021 Jul;31(4):1177-1190. doi: 10.1007/s10895-021-02746-9. Epub 2021 May 25.

Authors

Victoria T Olayemi^{1

2}, Adedibu C Tella^{3

4}, Folahan A Adekola¹, Hadley S Clayton⁵, Adetola C Oladipo^{1

6}, Gift Mehlana⁷, Adeniyi S Ogunlaja⁸, Oluwatobi S Oluwafemi⁹, Joseph O Ogar¹⁰, Stephen P Argent¹⁰, Robert Mokaya¹⁰

Affiliations

¹ Department of Chemistry, University of Ilorin, P.M. B 1515, Ilorin, Kwara State, Nigeria.
² Department of Chemistry, Faculty of Pure and Applied Sciences, Kwara State University, P.M. B 1530, Malete, Nigeria.
³ Department of Chemistry, University of Ilorin, P.M. B 1515, Ilorin, Kwara State, Nigeria. ac_tella@yahoo.co.uk.
⁴ Department of Chemistry, University of South Africa, Pretoria, South Africa. ac_tella@yahoo.co.uk.
⁵ Department of Chemistry, University of South Africa, Pretoria, South Africa.
⁶ Department of Physical Sciences, Landmark University, Omu-Aran, Kwara State, Nigeria.
⁷ Department of Chemical Technology, Faculty of Science and Technology Midlands State University (MSU), Gweru, Zimbabwe.
⁸ Department of Chemistry, Nelson Mandela University, P.O. Box 77000, Port Elizabeth, 6031, South Africa.
⁹ Department of Applied Chemistry, University of Johannesburg, Johannesburg, South Africa.
¹⁰ School of Chemistry, University of Nottingham, NG7 2RD, University Park, Nottingham, UK.

PMID: 34032972
DOI: 10.1007/s10895-021-02746-9

Abstract

A luminescent Cobalt(II) co-crystal [Co₁₃(PDC)₁₆(H₂O)₂₄.7H₂O] 1 (where H₂PDC = 2,6-pyridinedicarboxylic acid) have been prepared by oven-heating and slow evaporation of solvent. Single crystal X-ray diffraction (SCXRD) analysis revealed that 1 is a mixture of complexes that crystallizes in the triclinic space group P-1 and the geometry around the Co(II) ions is octahedral. The structure is extensively imbued with hydrogen bonding that helps in stabilizing the complex. Thermogravimetric analysis indicates that 1 is thermally stable up to 364 ^οC. The luminescence properties of 1 revealed a strong emission centered at 437 nm (λex = 345 nm) assigned to ligand to metal charge transfer (LMCT). The luminescence sensing of 1 towards volatile organic molecules were also examined. However, 1 displayed a turn off towards methanol compared to other molecules with high quenching efficiency and low limit of detection (3.5 × 10^-4 vol%). The results show excellent selectively and high sensitivity. Powder X-ray diffraction studies revealed that the structural integrity of the complex was maintained after exposure to methanol vapour. Theoretical studies also revealed small binding energy (-413.2 au) and low energy gap (1.19) for 1-CH₃OH adduct.

Keywords: Luminescence; Quenching; Single crystal XRD; Solvothermal; Triclinic.

Grants and funding

N/A/Royal Society of Chemistry