Central Metal Atom Research Articles

Highly sensitive and selective sensing of acetone and hydrogen sulfide using metal phthalocyanine – carbon nanotube hybrids

Noncovalent functionalization of carbon nanotubes with metal phthalocyanine has great potential for sensor nanodevices, nevertheless, some aspects of their electron transport mechanism behind the sensing properties have not been understood yet. Here, we evaluate the sensing performance of metal phthalocyanine – carbon nanotube hybrids for acetone and hydrogen sulfide (H2S) detection in terms of sensitivity and selectivity, using density functional theory and the non-equilibrium Green’s function method. We systematically investigated the effects of central transition metal atoms (Fe, Co, and Mn) of metal phthalocyanine with different chiralities (quasi-metallic CNT (9,0) zigzag and metallic CNT(5,5) armchair) of single-walled carbon nanotubes and tuning the gate voltages making this nanosensor highly sensitive and selective to acetone and H2S.

Influence of the Composition of the Hybrid Filler on the Atomic Oxygen Erosion Resistance of Polyimide Nanocomposites.

The structure and properties of nanocomposites based on organosoluble polyimide (PI) and branched functional metallosiloxane oligomers with different types of central metal atoms (Al, Cr, Fe, Zr, Hf and Nb) were investigated. Under the same weight content of the filler, the geometric parameters of the nanoparticles and thermal properties of the nanocomposites did not exhibit a direct relationship with the ability of the materials to withstand the incident flow of oxygen plasma. The atomic oxygenerosion resistance of the filled PI films was influenced by the composition of the hybrid fillerand the type of metal atom in the hybrid filler in the base metallosiloxane oligomer. To determine the effectiveness of the nanoparticles as protective elements of the polymer surface, the nanocomposite erosion yields pertaining to the concentration of the crosslinked organo–inorganic polymer forming the dispersed phase were determined and expressed in mmol per gram PI. The filler concentration in the polymer, expressed in these units, allows for comparison of the efficiency of different nanosize fillers for use in fabricating space survivable coatings. This can be important in the pursuit of new precursors, fillers for fabricating space survivable polymer composites.

Molecular docking study of the anticandida activity some schiff bases and their complexes

The research study entails the molecular docking study of some recently designed Schiff base complexes and their ligands (Schiff base) on two receptors, a crystal structure of Candida albicans Mep2 (5AF1) and a thiamin pyrophosphokinase from Candida albicans (2G9Z). These two receptors were used to investigate the inhibitory potentials of some Schiff bases on candida albicans when coupled with a central metal atom. The docking results for 2G9Z the complex A3 had the best binding affinity of 21.473 kcal/mol, while for 5AF1 the complex A4 best inhibits the crystal structure with a binding affinity of 23.518 kcal/mol. Showing that in both case the activity of the ligands was improved when the Schiff bases were coupled with a Lewis acid (metal ion) as its central metal atom.

Molecular and supramolecular structures of self-assembled Cu(II) and Co(II) complexes with 4,4’-[6-(3,5-dimethyl-1H-pyrazol-1-yl)-1,3,5-triazine-2,4-diyl]dimorpholine ligand

The molecular and supramolecular structures of [Cu(PTM)Cl2]∗0.75MeOH (1), [Co(PTM)Cl2]; (2A) and [Co(PTM)Cl2(EtOH)]; (2B) complexes, where PTM is 4,4’-[6-(3,5-dimethyl-1H-pyrazol-1-yl)-1,3,5-triazine-2,4-diyl]dimorpholine, were presented. In complexes 1 and 2A, the Cu(II) and Co(II) are tetra-coordinated with a distorted tetrahedral coordination environment. In case of complex 2B, an additional ethanol molecule is found coordinated with Co(II) leading to a highly distorted penta-coordinated Co(II) complex. In all cases, the PTM ligand is acting as a bidentate NN-chelate. Hirshfeld surface analysis indicated the importance of H⋯H (49.0–55.1%), Cl⋯H (18.8–20.5%) and O⋯H (8.3–9.9%) contacts in the molecular packing. The electron transferences from the ligand units to the central metal atom as well as the spin density distribution were discussed based on DFT calculations. The presence of coordinated ethanol molecule in 2B weakened the Co-N and Co-Cl interactions compared to 2A. Using atoms in molecules topology analysis, the coordinate bonds between metal (Co or Cu) and donor atoms (N, O, Cl) belong to closed shell interactions with weak covalent characters.

Physisorption and Chemisorption of SF6 by Transition Metal-Porphyrin Structure Embedded on Graphene Surface with Different Hapticities

The adsorption of sulfur hexafluoride (SF6) by a transition metal-porphyrin structure embedded on the surface of graphene (MN4-graphene) was evaluated using first-principles density functional theory calculations by constructing the adsorption energy profile. The mutual balance between physisorption and chemisorption was assessed by analyzing the characteristics of the interaction between each central metal atom as an adsorption center and the SF6 molecule. CaN4- and CrN4-graphene had moderate adsorption energies of about -1.5 eV. The results indicate the feasibility of these species as reusable SF6 adsorbents, even under ambient conditions. This study provides deeper insight into the adsorption of SF6 and the potential of transition metal-porphyrin structures as SF6 capture materials for mitigating global warming.

Highly soluble HOPEMP-functionalized phthalocyanines for photodynamic activity: Photophysical, photochemical and aggregation properties

This study presents the synthesis, characterization, photochemical, photophysical and aggregation properties of novel 4-((1,2,2,6,6-pentamethylpiperidin-4-yl)oxy)phthalonitrile (HOPEMP-Pht) and its highly soluble peripherally tetra-substituted Mg(II) (HOPEMP-MgPc), Zn(II) (HOPEMP-ZnPc), and In(III)CI (HOPEMP-InPc) phthalocyanine derivatives as a photosensitizer for photodynamic therapy (PDT) application. The novel compounds were characterized using various techniques. These phthalocyanines exhibit good solubility in many common organic solvents such as dimethyl-formamide, dimethyl sulfoxide, tetrahydrofuran, acetonitrile, acetone, chloroform, diethyl ether, dichloromethane, ethyl acetate, ethanol, methanol, hexane, and toluene. Aggregation behaviors of the HOPEMP-functionalized phthalocyanines were researched in different concentrations of dimethyl sulfoxide. To evaluate the photodynamic therapy potential of these phthalocyanines, photochemical and photophysical properties were examined in dimethyl sulfoxide for the first time. Besides, the effects of the nature of central metal atom on photochemical and photophysical properties of these phthalocyanines are also stated. As a result; singlet oxygen, photodegradation, fluorescence and aggregation properties show that these phthalocyanines can be promising photosensitizers for PDT studies.

On-Surface Supramolecular Chemistry with Porphyrins and Phthalocyanines: An Architectural Concept Leading to Engineered Quantum-Functional Nanostructures

The availability of porphyrin and phthalocyanine functionalization and synthesis, ‘by design’, at the time when sub-molecular resolution imaging at surfaces came into action boosted the emergence of ‘On-Surface-Supramolecular Chemistry’. [1] It is instructive to compare supra-molecular binding motifs in the fluid phase with the corresponding or modified analogues found after assembly on surfaces. In some similarity to chemistry and coordination chemistry translating into the corresponding ‘on-surface’ sciences, there are many factors complicating the on-surface assembly and architecture. Examples are provided by the modified dimensionality and kinetics, the site-specific conformational flexure and chirality and the close to irreversible adsorption in the strong surface potential in absence of a solvent which may complicate the on-surface assembly and architecture. Further, porphyrins and phthalocyanines interact with the substrate by different, competitive interactions, i.e. via (1) the central metal atom and (2) the porphyrin pi-system in addition to (3) the functional side groups. Binary and ternary assemblies of porphyrins and other functional components make it possible to create a wealth of ‘phases’, i.e. different complex supramolecular architectures with interesting physical properties to explore and exploit.We analyze structure-function correlations for a broad spectrum of functionalized porphyrins and phthalocyanines in their propensity to create structures of increasing complexity and functionality, on surfaces, also for future quantum technology. Notably, the large delocalized electronic system of the porphyrins and their easy-to-replace central atom further extend the achievable range of architectures and functions. Thus, by their dance on the nose of the ‘devil’ [3], porphyrins and phthalocyanines justify the emergence of ‘on-surface supramolecular physics’ as reflected by ongoing and future research work.[1] N. Wintjes et al. Two-dimensional phase behavior of a bimolecular porphyrin system at the solid-vacuum interface, J. Am. Chem. Soc. 2010, 132, 21, 7306-7311; N. Wintjes et al., Supramolecular synthons on surfaces: Controlling dimensionality and periodicity of tetraarylporphyrin assemblies by the interplay of cyano and alkoxy substituents Chem. Eur. J. 2008, 14, 5794.[2] S. Nowakowska et al., Adsorbate-induced modification of the confining barriers in a quantum box array, ACS Nano 2018, 12, 768.[3] W. Pauli “God made the bulk; surfaces were invented by the devil.” Quoted, e.g. in the Preface of A. Zangwill, Physics at Surfaces, Cambridge University Press, 1988. ISBN 978-0-521-34752-5Fig. 1) Adsorbate-induced modification of the confining barriers in a quantum box array formed by a functionalized fluoro-bi-phenyl porphyrin on Ag(111). (Taken from [2]) Figure 1

Interfacial Interaction of Absorbate Copper Phthalocyanine with PVDF Based Ferroelectric Polymer Substrates: A Spectroscopic Study.

Studies of CuPc thin films on underlying ferroelectric copolymeric and terpolymeric substrates have been performed by ultraviolet photoelectron spectroscopy (UPS), X-ray photoelectron spectroscopy (XPS), and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. Work function (WF) and highest occupied molecular orbital (HOMO) energy level shift observed from UPS spectroscopy for successive deposition of CuPc molecules on ferroelectric polymer surfaces confirm the formation of interface dipole at the CuPc-ferroelectric polymer interface owing to charge transfer from the tailing region of the CuPc HOMO density of states (DOS) to the ferroelectric polymer layer. According to our thickness dependent XPS data, CuPc molecules are coupled to the organic ferroelectric surfaces through the central metal atom of the CuPc molecules, i.e., copper atom, and the halogens of underlying ferroelectric polymer surfaces, and hence support the charge transfer phenomenon from CuPc molecules to the ferroelectric polymer substrate. Polarization dependent NEXAFS results reveal that CuPc molecules retain their tilted geometrical configuration even at submonolayer thickness of the molecular films on both ferroelectric surfaces and confirms the electronic structural disturbance associated with structural modification of CuPc molecules due to interfacial charge transfer. Therefore, the energy level alignment with increment in the thickness of CuPc films at both the organic semiconductor-ferroelectric polymer interface is controlled by the charge transfer phenomenon from deposited CuPc molecules to the organic ferroelectric substrates. Our results provide a clear understanding about chemical interactions, molecular configurations, energy level alignment, and their correlation at CuPc/polymeric ferroelectric interfaces that can be important for organic nonvolatile memory and synaptic based thin-film transistor devices.

Fluorine-Containing Tetraarylantimony Carboxylates: Synthesis and Structure

Tetraarylantimony carboxylates Ph4SbOC(O)R (R = CF2Br (I), CF2CF2CF3 (II)), (4‑MeC6Н4)4SbOC(O)CF2CF3 (III), and (4-MeC6Н4)4SbOC(O)CF2CF2CF3 (IV) have been synthesized by the reaction between pentaarylantimony Ar5Sb (Ar = Ph, 4-MeC6H4) and fluorine-containing carboxylic acids. Despite an excess amount of carboxylic acid in the reaction mixture, it does not form any solvates Ar4SbOC(O)R ⋅ HOC(O)R with tetraarylantimony carboxylates. X-ray diffraction shows that the Sb atoms in complexes I–IV have differently distorted trigonal bipyramidal coordination. Crystals of complexes III and IV contain two types of crystallographically independent molecules. The axial СSbO angles in complexes I, II, III, and IV are 175.32(14)°, 178.87(8)°, 178.56(13)° and 178.33(10)°, 178.16(13)°, and 179.58(15)°, respectively. The Sb–O and Sb–С bond lengths are 2.333(3) and 2.106(4)–2.151(5) A in I, 2.340(2) and 2.101(2)–2.154(3) A in II, 2.364(3), 2.411(3), and 2.096(4)–2.159(4) A in III, and 2.376(3), 2.367(3), and 2.105(4)–2.161(4) A in IV. The intramolecular Sb⋅⋅⋅O distances with the carbonyl oxygen atom are 3.506(4) A (I), 3.517(6) A (II), 3.565(6) A (III), and 3.527(6) A (IV), being ~0.2 A smaller than the sum of Sb and O van der Waals radii. The second carbonyl oxygen atoms in crystals of complexes III and IV do not participate in the coordination with the central metal atom.

Modulating the local coordination environment of single-atom catalysts for enhanced catalytic performance

The local coordination environment of catalysts has been investigated for an extended period to obtain enhanced catalytic performance. Especially with the advancement of single-atom catalysts (SACs), research on the coordination environment has been advanced to the atomic level. The surrounding coordination atoms of central metal atoms play important roles in their catalytic activity, selectivity and stability. In recent years, remarkable improvements of the catalytic performance of SACs have been achieved by the tailoring of coordination atoms, coordination numbers and second- or higher-coordination shells, which provided new opportunities for the further development of SACs. In this review, the characterization of coordination environment, tailoring of the local coordination environment, and their related adjustable catalytic performance will be discussed. We hope this review will provide new insights on further research of SACs.

Electrochemistry of icosahedral cobalt bis(dicarbollide) ions and their carbon and boron substituted derivatives in aqueous phosphate buffers

Herein we present investigations of electrochemical behavior over a series of selected bisicosahedral cobalt bis(heteroborane)(1-) derivatives in aqueous phosphate buffers. This pilot study is focused on distinct effects connected with either exo-skeletal substitutions at boron atoms with bridging and non-bridging groups or by influence of endo-hedral replacement of four cage CH groups present in the parent cobalt bis(dicarbollide) ion by two isolobal sulfur groups. The substitutions can thus be utilized for an easy tuning of the electrochemical properties of these boron polyhedral ions and for optimizing their responses in two quite broad electrochemical windows. The former is found in the negative potential corresponding to the redox process on the central metal atom; the latter, which was not considered in the literature, is located in the positive potential region and is connected with core cage oxidation process. Such properties seem to provide promising potential for electroanalytical sensing of this family of heterometallaboranes in tissues and their use for electrolabelling of biopolymers.

Recent Developments on Emerging Properties, Growth Approaches, and Advanced Applications of Metallic 2D Layered Vanadium Dichalcogenides

AbstractThe electronic structures of transition metal dichalcogenides (TMDs) has a strong dependency on the d‐band electrons of the central metal (M) atom. In particular, trigonal prismatic coordinated (2H) and octahedral coordinated (1T) phases with distinct crystal structure‐property relationships. Extraordinarily diverse electrical properties ranging from semiconducting, semimetallic to intrinsic metallic basically underlie from different Fermi level locations. Amid all TMDs, most specifically metallic VX2 possess plenty of interesting physical properties among them superconductivity, electrical conductivity, charge density wave, optical and magnetism etc. have offered intriguing applications in the fields of condensed matter physics, materials and device physics over the last few decades. Further modification of these materials by defect engineering, Li intercalation, electron beam/light irradiation, alloying and dimensional tuning can lead several tunable device applications. Due to their superior mechanical flexibility, controllable electrical properties, planar fabrication and high surface to volume ratio etc., 2D metallic TMDs materials emerge as active material for sensing, energy storage, conversion and field emission applications. This review article aims to provide the insights on the recent developments of different emerging properties, growth approaches and applications of 2D metallic VX2 (X = S, Se and Te) and its heterojunctions.

Atomic oxygen erosion resistance of polyimides filled hybrid nanoparticles

In this paper, a new kind of space-durable nanocomposites has been prepared using one-step in situ method of filling organosoluble polyimides (PI). Three types of metalloalkoxysiloxanes (tris-(diethoxymethylsiloxy) aluminum, tetrakis-(diethoxymethylsiloxy) zirconium, pentakis-(diethoxymethylsiloxy) niobium) were used as filler precursors. It is demonstrated that the nanosized filler particles formed in the polymer volume have a hybrid chemical structure and contain М-О-Si and Si–O–Si bonds. The in situ filling of PI preserves its unique thermal properties, increases the glass transition temperature, and maintains high stability to the thermal oxidation of the matrix PI. The atomic oxygen (AO) erosion resistance of the filled PI has been investigated by exposing its surface to a variety of AO fluences. The introduction of nanosized filler in PI contributes to a sharp, order-of-magnitude decrease in the AO erosion coefficient of the nanocomposite. The valence of the central metal atom of the precursor predetermines the silica-block content in the forming filler and its atomic oxygen AO-protective function. During the transition from a precursor with a trivalent metal atom to a precursor with a tetra- or pentavalent metal atom, the erosion coefficient of filled PI decreases at a constant fluence of AO. Taking into account that the M-O bond energy in a M-O-Si group is higher than the Si–O bond energy, the presence of such atoms as Zr or Nb in the chemical structure of the filler can act as a “reinforcing” element that increases the resistance of the protective layer against AO action.

Adsorption of Actinide (U-Pu) Complexes on the Silicene and Germanene Surface: A Theoretical Study.

Adsorption of actinide (Ac = U, Np, Pu) complexes with environmentally relevant ligands on silicene and germanene surfaces has been investigated using density functional theory to determine the geometrical, energetic, and electronic properties. Three types of ligands for each central metal atom are considered: OH-, NO3-, and CO32- with common oxo ligands in all cases. Among these, carbonate complexes show the strongest adsorption followed by hydroxide and nitrate. Two types of model, cluster and periodic models, have been considered to include the short- and long-range effects. The cluster and periodic models are complementary, although the former has not yet been widely used for studies of 2D materials. Two cluster sizes have been investigated to check size dependency. Calculations were performed in the gas phase and water solvent. On the basis of the adsorption energy, for the CO32- and OH- ligands, the bond position between two Si atoms in the silicene sheet is the most strongly adsorbed site in the cluster model for silicene whereas in the periodic model these complexes exhibit strong binding on the Si atom of the silicene surface. The Ac complexes with the NO3- ligand show strong affinity at the hollow space at the center of a hexagonal ring of silicene in both models. The H site is most favorable for the binding of complexes on the germanene cluster whereas these sites vary in the periodic model. Electronic structure calculations have been performed that show a bandgap range from 0.130 to 0.300 eV for the adsorption of actinide complexes on silicene that can be traced to charge transfer. Density of states calculations show that the contribution of the nitrate complexes is small near the Fermi level, but it is larger for the carbonate complexes in the silicene case. Strong interactions between Ac complexes and silicene are due to the formation of strong Si-O bonds upon adsorption which results in reduction of the actinide atom. Such bonding is lacking in germanene.

Single pot reaction of Co(III) and Ni(II) hydrogen-bonded organic frameworks and multidisciplinary application in dye adsorption, separation and DNA binding

Two hydrogen-bonded organic frameworks (HOFs) of formula Co(C6H5N2O)3 (1) and [Ni(C6H6N2O)3]·H2O·ClO4 (2) were synthesized by single pot reaction from the respective Syn-2-pyridinealdoxine (2-pdad) with separate reaction of Co(acac)2 and Ni(ClO4)2 in MeOH. X-ray crystallography exposes that (1) and (2) crystallized in orthorhombic and monoclinic space group with Pbca and P21/c point group, respectively. In both complexes, the central metal atoms are surrounded by three molecules of 2-pdad through chelation with the nitrogen atom of the aldoxin moiety and form a hexa-coordinated octahedral complex. Complexes (1) and (2) have van der Waals interaction, intra and intermolecular hydrogen bonding and rare 3D pillar layer HOFs network. However, both complexes adsorbed Rhodamine B (RhB) compared to other dyes i.e methylene blue and methyl orange. The % of adsorption efficiency of RhB is high in presence of complex 1, whereas complex (2) has a high efficiency for separation of dye molecule (RhB and MB). Moreover, the UV absorption spectrum of (1) and (2) was measured and maximum absorption peaks appeared at 224 nm and 280 nm, which suggest that the cobalt (III) complex bind to DNA via an intercalation binding mode whereas nickel (II) complex cannot bind to DNA. DFT Study observed that complex 1 (singlet) has the highest ionisation potential energy and softness and lowest stability and hardness compared to complex 2 (singlet or triplet).

Recent Studies on Single Site Metal Alkoxide Complexes as Catalysts for Ring Opening Polymerization of Cyclic Compounds

The selection of the catalyst is central to being able to control features and to better understand microstructures of polymers. New single-site metal alkoxide catalysts allow chemists to prepare regio/stereo regular polymers or copolymers that meet increasingly demanding performance requirements. These catalysts produce high molecular weights polymers with narrow polydispersity indexes or living properties and essentially regular polymers in structures. This review includes the synthesis, activity, and mechanistic aspects of especially single-site metal alkoxide catalysts with examples from my previous studies and recently published similar articles, beginning with an extensive survey on the aluminum, titanium, zirconium, and tin catalysts used to make polyethers, polyesters, and their derivatives. This review also compares the effects of ligands, substituents on ligands, and central metal atoms on ROP reactions. This review will provide the basis for the researchers who seek the new synthesis and application of catalysts in the future.

The Application of Reversible Intramolecular Sulfonamide Ligation to Modulate Reactivity in Organometallic Ruthenium(II) Diamine Complexes.

Metallation of biomacromolecular species forms the basis for the anticancer activity of many metallodrugs. A major limitation of these compounds is that their reactivity is indiscriminate and can, in principle, occur in healthy tissue as well as cancerous tissue, potentially leading to side effects in vivo. Here we present pH-dependent intramolecular coordination of an arene-tethered sulfonamide functionality in organometallic ruthenium(II) ethylenediamine complexes as a route to controlling the coordination environment about the central metal atom. Through variation of the sulfonamide R group and the length of the tether linking it to the arene ligand the acidity of the sulfonamide NH group, and hence the pH-region over which regulation of metal coordination occurs, can be modulated. Intramolecular sulfonamide ligation controlled the reactivity of complex 4 within the physiologically relevant pH-region, rendering it more reactive towards 5ʹ-GMP in mildly acidic pH-conditions typical of tumour tissue compared to the mildly alkaline pH-conditions typical of healthy tissue. However, the activation of 4 by ring-opening of the chelate was found to be a slow process relative to the timescale of typical cell culture assays and members of this series of complexes were found not to be cytotoxic towards the HT-29 cell line. These complexes provide the basis for the development of analogues of increased potency where intramolecular sulfonamide ligation regulates reactivity and therefore cytotoxicity in a pH-dependent, and potentially, tissue-dependent manner.

Synthesis, Crystal Structure and Antimicrobial Activity of Poly [bis-and#181;-3,5-dinitro-2-oxidobenzoato) (py) Cu II

A novel Poly [bis-and#181;-3,5-dinitro-2-oxidobenzoato) (py) Cu II]/(C12H7CuN3O7) was synthesized by a self assemble method at room temperature. The molecular structure was determined by single-crystal X-ray analysis. The compound crystallizes in the monoclinic system, space group P 2 1/c with lattice parameters of a = 10.2143, b = 5.1651 and c = 26.608, α = 90, β = 99.720, γ = 90, Z = 4, V = 1383.60 (18) and#197;3.Pore size depicted from single crystal XRD data was 47and#197;. The central metal atom Cu (II) is coordinated with oxygen of carboxylates group and nitrogen atom of pyridine. The coordination polyhedron posses square pyramidal geometry is manifested by the N— Cu—O angle of 90o. The structure is composed of monomeric coordination units with the central copper (II) ion is not occupying a centre of symmetry.

Synthesis, Crystal Structure and Antimicrobial Activity of Poly [bis-and#181;-3,5-dinitro-2-oxidobenzoato) (py) Cu II

A novel Poly [bis-and#181;-3,5-dinitro-2-oxidobenzoato) (py) Cu II]/(C12H7CuN3O7) was synthesized by a self assemble method at room temperature. The molecular structure was determined by single-crystal X-ray analysis. The compound crystallizes in the monoclinic system, space group P 2 1/c with lattice parameters of a = 10.2143, b = 5.1651 and c = 26.608, α = 90, β = 99.720, γ = 90, Z = 4, V = 1383.60 (18) and#197;3.Pore size depicted from single crystal XRD data was 47and#197;. The central metal atom Cu (II) is coordinated with oxygen of carboxylates group and nitrogen atom of pyridine. The coordination polyhedron posses square pyramidal geometry is manifested by the N— Cu—O angle of 90o. The structure is composed of monomeric coordination units with the central copper (II) ion is not occupying a centre of symmetry.

First cobalt complexes with methyl pyruvate semi/thiosemicarbazone - synthesis, physico-chemical and structural characterization

In the reaction of acetone solutions of CoX2?nH2O (X = Cl, Br) with methyl pyruvate semi/thiosemicarbazone (Hmps, Hmpt) the first Co(II) complexes with these ligands, i.e., [Co(Hmps)(H2O)X2] (X = Cl (1), Br (2)), [Co(Hmpt)2][CoCl4]?2H2? (3) and [Co(Hmpt)2]Br2?Me2CO (4) were obtained. Complexes 1 and 2 represent the first examples of metal complexes of Hmps. All the obtained compounds were characterized by elemental analysis, conductometry, magnetic measurements, and IR spectra, and for complexes 2?4, single crystal X-ray diffraction analysis was also performed. The effective magnetic moments were close to the upper limit (5 ?B) for complexes 1 and 2, and close to the lower limit (4.4 ?B) for complexes 3 and 4, and as such are characteristic for high-spin Co(II) complexes. Structural analysis showed that both ligands coordinate in a neutral form in a tridentate manner, via the ester oxygen, imine nitrogen and the oxygen atom of the ureido (Hmps), or the sulfur atom of the thioureido group (Hmpt). The central metal atoms are situated in a deformed octahedral coordination environment. Complex 2 has cis-Br configuration, while complexes 3 and 4 have mer-configuration.