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Robson ME, Johnson AL. Zinc and cadmium thioamidate complexes: rational design of single-source precursors for the AACVD of ZnS. Dalton Trans 2024; 53:11380-11392. [PMID: 38896487 DOI: 10.1039/d4dt01278j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
A series of zinc(II) thioamidate complexes [Zn{SC(iPr)NR}2]n for R = iPr (n = 2) (2), tBu (3) (n = 1), Ph (4) (n = 2) and Cy (5) (n = 2) and one cadmium(II) thioamidate complex [Cd{SC(iPr)NtBu}2]3, (6), were designed and synthesised as single-source precursors for AACVD ZnS and CdS. Solid-state structures of all four zinc(II) compounds revealed distorted tetrahedral or trigonal bipyramidal geometries, with varying tendencies for dimeric association, mediated by {Zn-S} bridging bonds. The thermogravimetric analysis identified the {tBu} derivertive, 3, as the most promising precursor based on its low decomposition onset (118 °C) and clean conversion to ZnS. This was attributed to the greater availability of β-hydrogen atoms promoting the pyrolysis mechanism. The corresponding cadmium thioamide 6 was found to crystallise as a trimetallic molecule which lacked the thermal stability to be considered viable for AACVD. Hence, 3 was used to deposit ZnS thin films by AACVD at 200-300 °C. Powder X-ray diffraction confirmed phase-pure growth of hexagonal wurtzite ZnS, with approximate crystallite sizes of 15-20 nm. Scanning electron microscopy revealed densely packed spherical nanoclusters. The morphology and crystallinity were most consistent for depositions between 250-300 °C. Energy dispersive X-ray spectroscopy indicated slightly sulfur-deficient stoichiometries.
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Affiliation(s)
- Max E Robson
- Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
- Centre of Doctoral Training in Aerosol Science, University of Bristol, School of Chemistry, Cantock's Close, BS8 1TS, UK
| | - Andrew L Johnson
- Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
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de Miranda DB, Quintal S, Ferreira GB. Electronic analysis of n-propyl xanthate complexes with group 12 metals: a theoretical-experimental study. J Mol Model 2024; 30:163. [PMID: 38730058 DOI: 10.1007/s00894-024-05950-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 04/18/2024] [Indexed: 05/12/2024]
Abstract
CONTEXT Xanthates are organic compounds of great interest in coordination chemistry due to their different basic sites, which allow them to form complexes with different coordination modes and geometries. These compounds are relevant in the environment and act as heavy metal collectors in aqueous environments. In this theoretical-experimental work, electronic spectroscopy studies of n-propyl xanthate complexes with group 12 metals were performed. This study verified structural differences in these systems, depending on the environment in which they are inserted. In addition, structural differences were observed when the solid was changed to an n-hexane solution. Thus, it was observed that the complexes assume a mononuclear structure in solution, while they present a polymeric form in the solid phase. The electronic spectra obtained through TD-DFT calculations were compared to those of the previously synthesized complexes. In the final theoretical analysis, the main orbitals involved in these transitions were assigned using population analysis calculations. The synthesis of the complexes was confirmed through infrared (MID and FAR), UV‒Vis, Raman, and NMR-1H spectroscopic analyses. METHODS The structures of the mononuclear and polymeric complexes were optimized in vacuum and n-hexane. Under vacuum, DFT levels M06L/6-311 + + G** + LANL2TZ and M06L/def2-TZVP were used for the mononuclear complexes, and M06L/LANL2DZ + LANL2 were used for the polymer complexes. For the calculations of the mononuclear complexes in n-hexane, the same level of theory was used for the solid state. TD-DFT calculations for 300 excited states were performed with the same levels of theory and used the optimized structures of the complexes. Furthermore, population analysis was carried out on all the systems studied. Gaussian 09 software was used for the structure optimization, TD-DFT, and population analysis calculations. GaussSum software was used to evaluate the molecular orbitals and electronic spectra.
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Affiliation(s)
- Daniella B de Miranda
- Programa de Pós-Graduação em Química, Instituto de Química, Universidade Federal Fluminense, Outeiro de S. João Batista s/n., Centro, Niterói, RJ, 24210-130, Brazil
| | - Susana Quintal
- Departamento de Química Inorgânica, Instituto de Química, Universidade Federal Fluminense, Outeiro de S. João Batista s/n., Centro, Niterói, RJ, 24210-130, Brazil
| | - Glaucio B Ferreira
- Programa de Pós-Graduação em Química, Instituto de Química, Universidade Federal Fluminense, Outeiro de S. João Batista s/n., Centro, Niterói, RJ, 24210-130, Brazil.
- Departamento de Química Inorgânica, Instituto de Química, Universidade Federal Fluminense, Outeiro de S. João Batista s/n., Centro, Niterói, RJ, 24210-130, Brazil.
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de Miranda DB, Quintal S, Ferreira GB. Theoretical studies of Zn 2+ complexes with alkyl xanthate ligands: a thermochemical, electronic energy decomposition, and natural bond orbital analysis. J Mol Model 2023; 29:203. [PMID: 37280464 DOI: 10.1007/s00894-023-05604-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Accepted: 05/23/2023] [Indexed: 06/08/2023]
Abstract
CONTEXT Xanthates are organic compounds that present great interest for coordination chemistry, because they can bond in different ways to the metal ion. Thus, these compounds have several applications, being best known for their environmental application. In fact, xanthates are recognized for their application as heavy metal collector agents in aqueous environments. In view of this application, this study is aimed at showing the thermochemical and electronic parameters obtained for the reactions of substitution water molecules in the aqua zinc complexes, by xanthate ligands (n-propyl, n-butyl, and n-pentyl xanthates). In addition to their environmental application, xanthates have shown biological properties, such as anti-bacterial and anti-cancer. In recent years, xanthates have also been used in the technological area, where it participates as a precursor of sulfides for the manufacture of thin films. Our results showed complexes with distorted octahedral geometries and with negative values of enthalpy and Gibbs free energy, indicating exothermic and spontaneous processes. For all the complexes, it was observed that Zn2+ complexes have both an ionic and covalent character. However, the monosubstituted complexes showed a predominance of the ionic character. In addition, high donor-acceptor interaction energies were obtained, indicating a good superposition between the s and p orbitals involved in the Zn-S bond. METHODS This work consists in theoretical studies of Zn2+ complexes with alkyl xanthate ligands, with different structures, where optimization and normal modes calculations were performed at different DFT levels: M06L, M06-2X, wB97XD, and B3LYP/6-311++G**+LANL2TZ, with Gaussian09 program. The process of substitution of two aqua by two xanthate ligands was analyzed in stages, forming cationic and neutral complexes, in the first and second stages, respectively. In addition, electronic energy decomposition (EDA) and natural bond orbital (NBO) analysis were performed at level M06L/6-311++G**+LANL2TZ with Gamess program.
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Affiliation(s)
- Daniella B de Miranda
- Programa de Pós-Graduação em Química, Instituto de Química, Universidade Federal Fluminense, Outeiro de S. João Batista s/n., Centro, Niterói, RJ, 24210-130, Brazil
| | - Susana Quintal
- Departamento de Química Inorgânica, Instituto de Química, Universidade Federal Fluminense, Outeiro de S. João Batista s/n., Centro, Niterói, RJ, 24210-130, Brazil
| | - Glaucio B Ferreira
- Programa de Pós-Graduação em Química, Instituto de Química, Universidade Federal Fluminense, Outeiro de S. João Batista s/n., Centro, Niterói, RJ, 24210-130, Brazil.
- Departamento de Química Inorgânica, Instituto de Química, Universidade Federal Fluminense, Outeiro de S. João Batista s/n., Centro, Niterói, RJ, 24210-130, Brazil.
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Hao XL, Chu XS, Luo KL, Li W. Host (CdS)-guest (single-atomic Au) electron transfer mechanism for blue-LED-induced atom transfer radical addition of alkenes. J Catal 2022. [DOI: 10.1016/j.jcat.2022.05.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Buckingham MA, Norton K, McNaughter PD, Whitehead G, Vitorica-Yrezabal I, Alam F, Laws K, Lewis DJ. Investigating the Effect of Steric Hindrance within CdS Single-Source Precursors on the Material Properties of AACVD and Spin-Coat-Deposited CdS Thin Films. Inorg Chem 2022; 61:8206-8216. [PMID: 35583220 PMCID: PMC9157504 DOI: 10.1021/acs.inorgchem.2c00616] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
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Cadmium sulfide (CdS)
is an important semiconductor for electronic
and photovoltaic applications, particularly when utilized as a thin
film for window layers in CdTe solar cells. Deposition of thin-film
CdS through the decomposition of single-source precursors is an attractive
approach due to the facile, low-temperature, and rapid nature of this
approach. Tailoring the precursor to affect the decomposition properties
is commonly employed to tune desirable temperatures of decomposition.
However, altering the precursor structure and the effect this has
on the nature of the deposited material is an area far less commonly
investigated. Here, we seek to investigate this by altering the ligands
around the Cd metal center to increase the steric hindrance of the
precursor and investigate the effect this has on the decomposition
properties and the properties of deposited thin-film CdS from these
precursors. For this, we report the synthesis of four CdS precursors
with xanthate and pyridyl ligands ([Cd(n-ethyl xanthate)2(3-methyl pyridine)2] [1], [Cd(n-ethyl xanthate)2(3,5-lutidine)2] [2], [(Cd2(isopropyl xanthate)4(3-methyl
pyridine)2)n] [3], and [Cd(isopropyl xanthate)2(3,5-lutidine)2] [4]). These single-source precursors for CdS were
fully characterized by elemental analysis, NMR spectroscopy, single-crystal
X-ray diffraction (XRD), and thermogravimetric analysis. It was found
that even with subtle alterations in the xanthate (n-ethyl to isopropyl) and pyridine (3-methyl and 3,5-dimethyl) ligands,
a range of hexa-coordinate precursors were formed (two with cis configuration, one with trans configuration, and one
as a one-dimensional (1D) polymer). These four precursors were then
used in aerosol-assisted chemical vapor deposition (AACVD) and spin-coating
experiments to deposit eight thin films of CdS, which were characterized
by Raman spectroscopy, powder X-ray diffraction, and scanning electron
microscopy. Comparative quantitative information concerning film thickness
and surface roughness was also determined by atomic force microscopy.
Finally, the optical properties of all thin films were characterized
by ultraviolet–visible (UV–Vis) absorption spectroscopy,
from which the band gap of each deposited film was determined to be
commensurate with that of bulk CdS (ca. 2.4 eV). Four single-source CdS precursors were
synthesized based
on a combination of xanthate- and pyridyl-derived ligands to investigate
increasing the steric hindrance of the precursor. Two cis, one trans, and one 1D polymer complexes were developed.
These precursors were then deposited as thin films through both spin
coating and aerosol-assisted chemical vapor deposition techniques,
and the morphology, film thickness, film surface roughness, particle
size distribution, and band gap energy were assessed.
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Affiliation(s)
- Mark A Buckingham
- Department of Materials, The University of Manchester, Manchester M13 9PL, U.K
| | - Kane Norton
- Department of Materials, The University of Manchester, Manchester M13 9PL, U.K
| | - Paul D McNaughter
- Department of Chemistry, The University of Manchester, Manchester M13 9PL, U.K
| | - George Whitehead
- Department of Chemistry, The University of Manchester, Manchester M13 9PL, U.K
| | | | - Firoz Alam
- Department of Chemistry, The University of Manchester, Manchester M13 9PL, U.K
| | - Kristine Laws
- Department of Chemistry, King's College London, London SE1 1DB, U.K
| | - David J Lewis
- Department of Materials, The University of Manchester, Manchester M13 9PL, U.K
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Preparation of nano Arsenic(III) sulfide from arsenic(III)-dithiocarbamate precursors: Synthesis, spectral, single crystal X-ray structural, BVS and CSM analysis of tris(disubstituteddithiocarbamato)arsenic(III) complexes. Polyhedron 2021. [DOI: 10.1016/j.poly.2021.115405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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