TY - JOUR

T1 - Octachlorinated Metal Phthalocyanines (M = Co, Zn, VO): Crystal Structures, Thin-Film Properties, and Chemiresistive Sensing of Ammonia and Hydrogen Sulfide

AU - Kamdina, Tatiana

AU - Klyamer, Darya

AU - Sukhikh, Aleksandr

AU - Popovetskiy, Pavel

AU - Krasnov, Pavel

AU - Basova, Tamara

N1 - The study was funded by the Russian Science Foundation, grant number 24-73-10058.

PY - 2026

Y1 - 2026

N2 - Octachlorinated metal phthalocyanines (MPcCl8, M = Co, Zn, VO) represent an underexplored class of functional materials with promising potential for chemiresistive sensing applications. This work is the first to determine the structure of single crystals of CoPcCl8, revealing a triclinic (P-1) packing motif with cofacial molecular stacks and an interplanar distance of 3.381 Å. Powder XRD, vibrational spectroscopy, and elemental analysis confirm phase purity and isostructurality between CoPcCl8 and ZnPcCl8, while VOPcCl8 adopts a tetragonal arrangement similar to its tetrachlorinated analogue. Thin films were fabricated via physical vapor deposition (PVD) and spin-coating (SC), with SC yielding highly crystalline films and PVD resulting in poorly crystalline or amorphous layers. Electrical measurements demonstrate that SC films exhibit n-type semiconducting behavior with conductivities 2–3 orders of magnitude higher than PVD films. Density functional theory (DFT) calculations corroborate the experimental findings, predicting band gaps of 1.19 eV (Co), 1.11 eV (Zn), and 0.78 eV (VO), with Fermi levels positioned near the conduction band, which is consistent with n-type character. Chemiresistive sensing tests reveal that SC-deposited MPcCl8 films respond reversibly and selectively to ammonia (NH3) and hydrogen sulfide (H2S) at room temperature. ZnPcCl8 shows the highest NH3 response (45.3% to 10 ppm), while CoPcCl8 exhibits superior sensitivity to H2S (LOD = 0.3 ppm). These results suggest that the films of octachlorinated phthalocyanines produced by the SC method are highly sensitive materials for gas sensors designed to detect toxic and corrosive gases.

AB - Octachlorinated metal phthalocyanines (MPcCl8, M = Co, Zn, VO) represent an underexplored class of functional materials with promising potential for chemiresistive sensing applications. This work is the first to determine the structure of single crystals of CoPcCl8, revealing a triclinic (P-1) packing motif with cofacial molecular stacks and an interplanar distance of 3.381 Å. Powder XRD, vibrational spectroscopy, and elemental analysis confirm phase purity and isostructurality between CoPcCl8 and ZnPcCl8, while VOPcCl8 adopts a tetragonal arrangement similar to its tetrachlorinated analogue. Thin films were fabricated via physical vapor deposition (PVD) and spin-coating (SC), with SC yielding highly crystalline films and PVD resulting in poorly crystalline or amorphous layers. Electrical measurements demonstrate that SC films exhibit n-type semiconducting behavior with conductivities 2–3 orders of magnitude higher than PVD films. Density functional theory (DFT) calculations corroborate the experimental findings, predicting band gaps of 1.19 eV (Co), 1.11 eV (Zn), and 0.78 eV (VO), with Fermi levels positioned near the conduction band, which is consistent with n-type character. Chemiresistive sensing tests reveal that SC-deposited MPcCl8 films respond reversibly and selectively to ammonia (NH3) and hydrogen sulfide (H2S) at room temperature. ZnPcCl8 shows the highest NH3 response (45.3% to 10 ppm), while CoPcCl8 exhibits superior sensitivity to H2S (LOD = 0.3 ppm). These results suggest that the films of octachlorinated phthalocyanines produced by the SC method are highly sensitive materials for gas sensors designed to detect toxic and corrosive gases.

KW - ammonia

KW - chemiresistive sensors

KW - hydrogen sulfide

KW - octachlorinated phthalocyanines

KW - single crystal structure

KW - thin films

UR - https://www.scopus.com/pages/publications/105027116632

UR - https://www.mendeley.com/catalogue/6aba8ce0-f740-3b53-92ff-1e94992af9ef/

U2 - 10.3390/s26010008

DO - 10.3390/s26010008

M3 - Article

C2 - 41516443

VL - 26

JO - Sensors

JF - Sensors

SN - 1424-3210

IS - 1

M1 - 8

ER -