Nitrogen Atom Of Ring Research Articles

Advances in the Chemistry of 6-6 Bicyclic Systems: Chemistry of Pyrido[3,4- d]pyrimidines.

The aim of this work is to discuss the chemistry of pyrido[3,4-d]pyrimidines as one of the most important heterocyclic compounds with remarkable synthetic, biological and medical applications. In this overview, the chemistry of heterocyclic compounds incorporated the pyrido[3,4-d]pyrimidine scaffold as demonstrated by chemical reactions and different preparation processes. The anticipated compounds were synthesized from pyridine or pyrimidine compounds and a description of the reactivity of substituents attached to ring carbon and nitrogen atoms is discussed. On the other hand, the synthesis and reactions of fused heterocycles incorporated pyrido[3,4-d]pyrimidine scaffold is described. The diamine analogs included pyrido[3,4-d]pyrimidine core were reported as tyrosine kinase inhibitors. The chemical reactions of certain unexpected and chemically substantial compounds have been discussed.

Crystal structure of 1,4-bis-[5-(2-meth-oxy-phen-yl)-2H-tetra-zol-2-yl]butane.

The title compound, C20H22N8O2, was synthesized by the coupling reaction of a sodium tetra-zolate salt and di-bromo-butane in a molar ratio of 2:1. The reaction can produce several possible regioisomers and the title compound was separated as the major product. The X-ray crystallographic study confirmed that the title compound crystallizes in the monoclinic P21/c space group and possesses a bridging butyl-ene group that connects two identical phenyl tetra-zole moieties. The butyl-ene group is attached not to the first but the second nitro-gen atoms of both tetra-zole rings. The dihedral angles between the phenyl groups and the adjacent tetra-zolyl rings are 5.32 (6) and 15.37 (7)°. In the crystal, the mol-ecules form centrosymmetric dimers through C-H⋯O hydrogen bonds between a C-H group of the butyl-ene linker and the O atom of a meth-oxy group.

Tuning the Photophysical Properties of Push-Pull Azaheterocyclic Chromophores by Protonation: A Brief Overview of a French-Spanish-Czech Project.

Conjugated push-pull molecules that incorporate nitrogen heterocycles as electron-withdrawing units are interesting materials because of their luminescence properties. These chromophores can be easily and reversibly protonated at the nitrogen atom of the heterocyclic ring and this can cause dramatic color changes. White and multi-color photoluminescence both in solution and in the solid state can be obtained by an accurate control of the amount of acid. Thus, with a suitable design these compounds have potential applications in the development of colorimetric pH sensors and the fabrication of OLEDs based on only one material. We provide here a brief overview of our collaborative efforts made in this area.

Synthesis, spectroscopic, thermal, and structural properties of cyanobridged metal complexes containing tetracyanonickelate(II) building blocks with 4-aminomethylpyridine

New cyano-bridged metal complexes with chemical formulas [Fe(NH3)2(ampy)Ni(CN)4]n, [Co(H2O)2(ampy)Ni(CN)4]n and [Ni(NH3)2(ampy)Ni(CN)4]n (ampy = 4-aminomethylpyridine, hereafter abbreviated as Fe–Ni–ampy, Co–Ni–ampy and Ni–Ni–ampy) were obtained in the form of powders and examined by vibrational (infrared and Raman) spectroscopy, thermal (TG, DTG and DTA), and elemental analysis techniques. The infrared and Raman spectra of the complexes were performed in the range of 4000–400 cm-1 and 4000–250 cm-1, respectively. General information about the structural features of synthesized complexes was obtained by considering the changes in the cyano group and characteristic peaks of ampy. The cleavage of the (CN) stretching bands in the infrared spectrum of the complexes shows that the terminal and bridge cyano groups are in the structure. Considering the variations in the vibrational frequencies of the cyano group and ampy ligand in the spectrum of the complexes, the Ni atom is in a square plane geometry with four cyano groups and two of these cyano groups are the bridge and the other two are terminal. In addition, the metal atoms [Fe(II), Co(II) or Ni(II)] are linked to the ring and amino nitrogen atoms of two symmetric ampy ligands, the two ammonia (two aqua ligands for Co–Ni–ampy) ligands and the two bridging cyano groups, and show a distorted octahedral geometry. The thermal degradation of the complexes was also studied between 30 and 950 ºC using TG, DTG, and DTA techniques.

A comparative theoretical study on the interaction of pure and carbon atom substituted boron nitride fullerenes with ifosfamide drug

Anticancer drug delivery is now becoming an important scientific challenge as it allows localizing drug release near the tumor cell and avoiding secondary side effects. Based on the density functional theory (DFT) calculations, the adsorption of Ifosfamide (IFO) on a series of pure B12N12 and carbon-doped boron nitride, including B12N6C6 and B6N6C12 fullerenes, was carried out both in vacuum and solvent (water) environment conditions by means of PBE-1 and M06-2X functionals and 6-311 + G (d,p) basis set. The most stable chemisorption state for the IFO was through phosphoryl group (−1.21 eV) onto the B12N12 in comparison with chloroalkyl (−0.35 eV) and nitrogen atom of oxazaphosphorine ring (−1.14 eV) groups. To compare both environments, the computed results indicate that the adsorption of IFO in the solvent environment is more stable on the B12N12 (−1.27 eV), B12N6C6 (−1.86 eV), and B6N6C12 (−1.99 eV) fullerenes than in the vacuum environment. Our computational simulations represent that the amount of IFO loading is higher for the fullerenes, on the other hand, the interaction energy of IFO with B6N6C12 is greater, which can reduce its release rate.

Synthesis of Pyridyl and N-Methylpyridinium Analogues of Rosamines: Relevance of Solvent and Charge on Their Photophysical Properties.

A series of pyridyl analogues of rosamines was prepared by employing two methodologies: (i) the conventional-heating condensation of a pyridinecarboxaldehyde with 3-(diethylamino)phenol in propionic acid, and (ii) the novel ohmic-heating assisted condensation under "on water" conditions, followed by oxidation. The 4-pyridyl substituted rosamine was further converted into the N-methylpyridinium derivative through N-alkylation using methyl iodide. The influence of the position and cationization of the nitrogen atom of the pyridyl ring in the physicochemical properties of fluorophores was investigated by 1 H, 13 C, 15 N NMR spectral analysis, UV/Vis and fluorescence spectroscopy, single-crystal X-ray diffraction (4-pyridyl and N-methylpyridinium derivatives) and thermal-behavior analysis. Curiously, for ethanolic solutions of 4-pyridyl and N-methylpyridinium derivatives an extinction of color and fluorescence over time was observed. This phenomenon was further studied and the data revealed that it is the result of nucleophilic addition of ethoxide ion to the central 9-position of the xanthene. The kinetics of the process is slower for the 4-pyridyl rosamine, which emphasizes the importance of the charge in the N-methylpyridinium analogue in the reactivity of the molecule towards a nucleophile agent. This phenomenon is reversible, meaning that the compounds can be rapidly recovered by decreasing the pH, opening new avenues in the sensing applications of this class of rosamines.

Correlation between molecular charge densities and sensitivity of nitrogen-rich heterocyclic nitroazole derivative explosives

Nitroazole derivatives are nitrogen-rich heterocyclic ring molecules with potential application as energetic materials. Thirty-three of them-nitroimidazoles, nitrotriazoles, and nitropyrazoles-were investigated. Computed density functional theory molecular charge densities were partitioned employing the accurate distributed multipole analysis (DMA) method. Based on the magnitude of the DMA atom-centered electric multipoles (monopole, dipole, and quadrupole values), mathematical models were developed to compute the impact sensitivity of the explosives composed of these molecules. Charge localization and delocalization of the ring nitrogen atoms as well as charges of the atoms of the nitro group affect the sensitivity of explosives composed of nitroazole derivatives. The sensitivity is strongly dependent on the ring position of the nitrogen atoms and the bonding site of the substituent groups. The N/C ratio and the repulsion of the non-bonding electron pairs of the vicinal nitrogen atoms of the ring also play an important role in the stability of nitroazoles. The influence of the withdrawing group (NO2) and the electron injector groups (NH2 and CH3) including their bonding position on the ring could be quantified.

A DFT Approach to the Surface-Enhanced Raman Scattering of 4-Cyanopyridine Adsorbed on Silver Nanoparticles.

A Surface-Enhanced Raman Scattering (SERS) spectrum of 4-cyanopyridine (4CNPy) was recorded on silver plasmonic nanoparticles and analyzed by using Density Functional Theory (DFT) calculations. Two simple molecular models of the metal–4CNPy surface complex with a single silver cation or with a neutral dimer (Ag+–4CNPy, Ag2–4CNPy), linked through the two possible interacting sites of 4CNPy (aromatic nitrogen, N, and nitrile group, CN), were considered. The calculated vibrational wavenumbers and intensities of the adsorbate and the isolated species are compared with the experimental Raman and SERS results. The analysis of the DFT predictions and the experimental data indicates that 4CNPy adsorbs preferentially on neutral/charged active sites of the silver nanoparticles through the nitrogen atom of the aromatic ring with a perpendicular orientation.

Crystal structure of metolazone, C16H16ClN3O3S

The crystal structure of metolazone has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Metolazone crystallizes in space group P-1 (#2) with a = 8.1976(5), b = 14.4615(69), c = 16.0993(86) Å, α = 115.009(18), β = 90.096(7), γ = 106.264(4)°, V = 1644.52(9) Å3, and Z = 4. The broad (02-1) peak at 3.42° 2θ indicates stacking faults along this direction. The crystal structure consists of alternating polar and hydrocarbon layers parallel to the ac-plane. Only one of the sulfonamide groups acts as a hydrogen bond donor. Both ring nitrogen atoms act as hydrogen bond donors, but one forms an N–H···N hydrogen bond, while the other participates in an N–H···O bond. The powder pattern has been submitted to ICDD® for inclusion in the Powder Diffraction File™, to replace entry 00-066-1624.

Synthesis, spectroscopy, and theoretical calculations of some 2-thiohydantoin derivatives as possible new fungicides

We present the synthesis and structure determination for two thiohydantoin compounds (5-benzylidene-2-sulfanylideneimidazolidin-4-one and 5-cinnamylidene-2-sulfanylideneimidazolidin-4-one), proposed as potential novel fungicides. The exact chemical structure of these molecules has not yet been determined since they can potentially exist in several tautomeric and geometric forms (Z-E isomerism). The geometries of all the theoretically possible structures of the studied compounds were optimised. The calculations were performed at the density functional theory level using the B3LYP functional and the 6-311++G** basis set. Based on our calculations, the most probable structures of the studied compounds were proposed. The theoretical predictions were verified by comparing the calculated IR as well as the 1H and 13C NMR spectra with the experimental data. It was documented that both the studied compounds exist predominantly in the tautomeric structure, in which the movable hydrogen is connected to the nitrogen atom in the hydantoin ring. It has been experimentally proven that one of the studied compounds occurs only as a single structure, whereas the other one exists as a mixture of two geometric isomers.Schematic presentation of synthesis reaction and predicted percentage contents of studied compounds in products mixture

Kinetics and mechanism of the oxidative degradation of sofosbuvir by N-bromosuccinimide in aqueous medium

The kinetics of the electron transfer in sofosbuvir (Sofo) using N-bromosuccinimide (NBS) in aqueous medium has been studied spectrophotometrically over the (10–30) °C range, (0.1–0.5) mol dm−3 ionic strength, pH = 6.0–8.0 range over a range of NBS and Sofo concentrations. The rate of reaction was first order dependence on both [NBS] and [Sofo] and decreased with increasing [H+] over the range studied suggesting that the deprotonated form of sofosbuvir is more reactive than its conjugate acid. The hydrogen atom attached to the nitrogen atom of pyrimidine dione ring has a highly acidic character due to withdrawing effect of the adjacent two carbonyl groups and so the sofosbuvir acted as an acid. The rate decreased with increasing the ionic strength of the reaction mixture and supported that the reaction took place between two ions of different charges.

Spectroscopic characterization and XRD of some new metal complexes with dithranol in presence of 8-hydroxyquinoline

IN THE PRESENT work, dithranol (Dithr) reacts with Ni(II), Zn(II), Zr(IV), La(III), and Th(IV) in presence of heterocyclic ligand 8-hydroxyquinoline (8HQ) in acetone forming new mixed ligand complexes. The structures of the synthesized complexes were characterized by conventional techniques including melting point, molar conductivity, magnetic properties, elemental analyses, infrared, ultraviolet-visible, 1H nuclear magnetic resonance, and X-ray powder diffraction (XRD) spectra, as well as thermogravimetric (TG) and differential thermogravimetric (DTG) analyses. The molar conductance values of the metal complexes in dimethyl sulphoxide (DMSO) indicated that the complexes were found to be electrolytes with different ratios. The magnetic susceptibility measurements for Ni(II) complex is 3.1 BM with distorted octahedral geometry. TG/DTG studies confirmed the chemical formula for these complexes and established the thermal decomposition processes ended with the formation of metal oxide contaminated with carbon atom. The infrared spectra of the complexes showed shift for ν(O-H) and ν(C=N) in all complexes, which indicated the coordination of oxygen atom of phenolic group and nitrogen atom of pyridine ring of 8HQ with metal ions. X-ray powder diffraction analysis of the compounds showed that Dithr, 8HQ, and their metal complexes display crystalline peaks except Zr(IV) and La(III) complexes.

Synthesis of Novel Benzimidazolium Gemini Surfactants and Evaluation of Their Anti-Candida Activity.

Owing to the rise in antimicrobial and chemotherapeutic drug resistance, there is a desperate need to formulate newer as well as more effective agents. With this perspective, here we outline the synthesis of two novel gemini surfactants with different substitutions at the nitrogen atom of the benzimidazolium ring. Both the compounds induced significant reductions in Candida growth in various yeast strains. The reduction in Candida growth seemed likely through the reduction in ergosterol biosynthesis: a sterol constituent of yeast cell membranes. Different concentrations of both compounds were used to determine the cellular ergosterol content which indicates an important disordering of the ergosterol biosynthetic pathway. Cytotoxic studies were carried out using HEK 293 (human embryonic-kidney cells) and Galleria mellonella larvae (an in vivo model of antimicrobial studies). Administration of both the compounds to G. mellonella larvae diseased by the yeast Candida albicans resulted in increased survival indicating their in vivo activity.

Spectroscopic and theoretical investigation into substituent- and aggregation-related dual fluorescence effects in the selected 2-amino-1,3,4-thiadiazoles

The article presents the results of spectroscopic studies conducted on three compounds from the 1,3,4-thiadiazole group: 2-amino-5-phenyl-1,3,4-thiadiazole (TB), 2-amino-5-(2-hydroxyphenyl)-1,3,4-thiadiazole (TS), 2-amino-5-(2-hydroxy-5-sulfobenzoyl)-1,3,4-thiadiazole (TSF). The fluorescence emission spectra of the previously reported TS analogue revealed an interesting dual fluorescence effect in butanol. Depending on the structural composition of the resorcylic system, for the other analogues two partially overlapping emission bands or single emission bands were observed. Interpretation of the UV–Vis spectra, stationary fluorescence, RLS, as well as fluorescence lifetimes allowed us to correlate said effects with the phenomenon of specific molecular aggregation which, depending on the substituent, can induce the process related to charge transfer within the given molecule. The conducted calculations of dipole moment changes for the ground and excited state, as well as the [TD] DFT calculations confirmed our assumptions with regard to the experimental results. The described study was also the first to analyse fluorescence effects, for this particular group of analogues, relative to primarily the structural composition of the first substituent by the thiadiazole ring. The correlation between said fluorescence effects and earlier measurements conducted on analogues in from this group of compounds in various systems (liposomes, micelles, or crystals) also suggests the possibility of charge transfer (CT) dependant on the appropriate conformation of the molecule (with the -OH group on the side of the nitrogen atom in the thiadiazole ring).It should be emphasised that this type of fluorescence effects can be relatively easily identified with the use of fluorescence methods, which means that fluorophores from this group can be used as ideal fluorescence probes which continue to be in high demand in the context of biology/molecular medicine.

Abstract 3839: Comparison of thio-deoxy-cytidine (TdCyd) and aza-thio-deoxy-cytidine (Aza-TdCyd) in solid and liquid tumor cell lines and PPTC pediatric xenografts

Abstract Cytidine analogs target DNA methyltransferases as at least one of their mechanisms of action. The mechanism(s) of action of these compounds are incompletely elucidated and vary. TdCyd and Aza-TdCyd are thio-nucleoside analogs of cytidine which differ by a single nitrogen atom in the cytidine ring. Here the activity in solid and liquid tumor cell lines, and pediatric tumor xenografts is compared. Methods: Cytotoxicity was examined after 2, 3 and 7-day exposure in 10 solid tumor lines and 6 liquid tumor lines. TdCyd was administered (1mg/kg) ip, daily for 5 days for 4 weeks (total 20 doses). Aza-TdCyd was administered (1.5, 1.0 or 0.5 mg/kg) ip, daily for 5 days for 4 weeks (total 20 doses). For solid tumors (sc), events were defined as 4X increase in tumor volume from day 0, for acute lymphoblastic leukemias (ALL) as %hCD45 cells exceeding 25%. The Kaplan-Meier method was used to compare time-to-event across treated and control groups. The objective response categories are progressive disease (PD), stable disease (SD), partial response (PR), complete response (CR), and maintained complete response (MCR) [Pediatr Blood Cancer 2007;49:928-40]. Results: Aza-TdCyd was, in general, a more active antitumor agent than TdCyd. In cell culture, after 7-days exposure Aza-TdCyd was 3-to 4-fold more potent than TdCyd in 10 solid tumor lines (IC50 1.2 vs 3.7 uM) and similarly more potent in 6 liquid tumor lines (0.03 vs 0.11 uM). TdCyd and Aza-TdCyd were tested in Ewing sarcoma, rhabdoid tumor, rhabdomyosarcoma, osteosarcoma, and pediatric acute lymphoblastic leukemia (ALL) patient-derived xenografts. The sarcomas were implanted subcutaneously, and the leukemias were implanted intravenously. At tolerable doses, the anticancer activity of both TdCyd and Aza-TdCyd were modest in the Ewing sarcoma (4) and rhabdomyosarcoma (4) models. The activity of both compounds was also modest in 5 out of 6 osteosarcoma models. However, the median survival of mice bearing the OS-9 osteosarcoma doubled (42 days) upon treatment with TdCyd and increased nearly 4-fold (84 days) in mice treated with Aza-TdCyd. While TdCyd had modest ALL activity, Aza-TdCyd increased median survival from 9.1(2-16) days in controls to >70 in 7/9 ALL models. Aza-TdCyd antileukemic activity was maintained at lower doses of the agent with median survivals of 75.4 days at 1.5mg/kg, 72.7 days at 1.0 mg/kg and 62.0 days at 0.5 mg/kg. Both TdCyd (NCT02423057) and Aza-TdCyd (NCT03366116) are in phase 1 clinical testing. Supported by NCI Grants: CA199222, CA199221, CA199297, CA199288, CA199000 and NCI Contract No. HHSN261200800001E. Citation Format: Beverly A. Teicher, Richard B. Lock, Kathryn Evans, Peter J. Houghton, Raushan T. Kurmasheva, Richard Gorlicki, Steve Erickson, Donn Wishka, Joel Morris, Michael Difilippantonio, Jerry E. Collins, Malcolm A. Smith, James H. Doroshow. Comparison of thio-deoxy-cytidine (TdCyd) and aza-thio-deoxy-cytidine (Aza-TdCyd) in solid and liquid tumor cell lines and PPTC pediatric xenografts [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3839.

Structural development of a type-1 ryanodine receptor (RyR1) Ca2+-release channel inhibitor guided by endoplasmic reticulum Ca2+ assay

Type-1 ryanodine receptor (RyR1) is a calcium-release channel localized on sarcoplasmic reticulum (SR) of the skeletal muscle, and mediates muscle contraction by releasing Ca2+ from the SR. Genetic mutations of RyR1 are associated with skeletal muscle diseases such as malignant hyperthermia and central core diseases, in which over-activation of RyR1 causes leakage of Ca2+ from the SR. We recently developed an efficient high-throughput screening system based on the measurement of Ca2+ in endoplasmic reticulum, and used it to identify oxolinic acid (1) as a novel RyR1 channel inhibitor. Here, we designed and synthesized a series of quinolone derivatives based on 1 as a lead compound. Derivatives bearing a long alkyl chain at the nitrogen atom of the quinolone ring and having a suitable substituent at the 7-position of quinolone exhibited potent RyR1 channel-inhibitory activity. Among the synthesized compounds, 14h showed more potent activity than dantrolene, a known RyR1 inhibitor, and exhibited high RyR1 selectivity over RyR2 and RyR3. These compounds may be promising leads for clinically applicable RyR1 channel inhibitors.

Hydrogen bonding and protonation effects in amino acids' anthraquinone derivatives - Spectroscopic and electrochemical studies.

Six novel amino acid chromophores were synthesized and their spectroscopic, acid-base, and electrochemical properties are discussed in this work. In studied compounds, selected amino acid residues (l-Aspartic acid, l-Glutamic acid, l-Glutamine, l-Histidine, l-Lysine, l-Arginine) are attached to the 1-(piperazine) 9,10-anthraquinone skeleton via the amide bond between the carboxyl group of amino acid and nitrogen atom of the piperazine ring. All derivatives have been characterized using a variety of spectroscopic techniques (mass spectrometry, 1HNMR, UV-Vis, IR spectroscopy), acid-base (electrochemical and UV-Vis) titrations, and cyclic voltammetry methods. Basing on observed experimental effects, supported by quantum chemical simulations, the structure-properties links were established. They are indicative of the specific interactions within and/or in-between amino acid side groups, which are prone to form both, intra- and intermolecular hydrogen bonds as well as electrostatic interactions with the anthraquinone system.

Synthesis, structures and magnetic properties of three cyclic lanthanide complexes with nitronyl nitroxide radical

Three new lanthanide complexes based on a nitronyl nitroxide radical [Ln(hfac)3(NIT3Ph3Py)]2 (Ln = Dy(1), Tb(2), Gd(3); hfac = hexafluoroacetylacetonate, NIT3Ph3Py = 2-(3′-(3″-pyridyl)-phenyl)-4,4,5,5- tetramethylimidazoline-1-oxyl-3-oxide) have been successfully synthesized, characterized structurally and magnetically. Single crystal X-ray diffraction analysis reveals that complexes 1–3 are isomorphous in which NIT3Ph3Py acts as a bridging ligand linking two Ln(III) ions through the nitrogen atom of pyridine ring and the oxygen atom of NO group to form a four-spin system. The magnetic studies reveal that the ferromagnetic interactions between the Ln(III) ions and nitronyl nitroxide radicals in the complexes. Moreover, alternating current (ac) magnetic susceptibilities show that Dy(III) complex exhibits frequency-dependent signals at low temperature.

Synthesis, Spectral Characterization and Microbial Activity of Ni (II) Complex with DBAP Schiff’s Base Ligand

Ni (II) complexes were synthetized from the Schiff Base Ligand. The Schiff base ligand [DBAP] (L) is prepared when 3,4- dimethoxy benzaldehyde reacts with 3- amino pyridine. Elemental Analysis, FTIR, UV analysis, HRMS, Magnetic Susceptibility and Molar Conductance data have concluded information regarding the nature of bonding and geometry of the transition metal complex as well as Schiff base Ligand. The Ligand (L) acts as bidentate and co-ordinate through Nitrogen atom of imine group (azomethine group) & Nitrogen atom of the Pyridine ring. Bacterias like E.coli and Bacillus Subtilis (by well disc and fusion method) were used to study the biological activity of the ligand and the Ni(II)complexes. Experimental data revealed that the metal chelates are more active than the free Schiff’s base ligand.

Synthesis, characterization and cytotoxic activity of tioconazole coordination compounds with nickel(II), palladium(II) and platinum(II)

Coordination compounds of nickel(II), palladium(II) and platinum(II) with tioconazole (tcnz) were synthesized and characterized by infrared, UV-Vis-NIR, elemental analysis, molar conductivity, magnetic susceptibility, mass spectrometry, NMR spectroscopy and X- ray diffraction. Tioconazole presented a monodentate coordination mode, through the nitrogen atom of the imidazolic ring. The NiII compounds stabilized an octahedral geometry. In [Ni(tcnz)2(NO3)2].H2O the coordinated nitrate presented a bidentate coordination mode, while for the [Ni(tcnz)2(OAc)2].3H2O compound, the acetate behaves as a bridging ligand. When different molar ratios were used on the reaction synthesis, three or six ligands were coordinate to the nickel(II) atom, [Ni(tcnz)3Br2(H2O)], [Ni(tcnz)6]Cl2 and [Ni(tcnz)6]Br2. The palladium(II) and platinum(II) compounds, [Pd(tcnz)2Cl2], [Pt(tcnz)2Cl2].2H2O and [Pd(tcnz)2(OAc)2], stabilized a trans-square planar geometry. The compounds [Ni(tcnz)6]X2 give place to 3D supramolecular arrangements through hydrogen bonding (X∙∙∙H, X = Cl and Br) and p∙∙∙p stacking interactions, between the six membered rings of neighbouring molecules. The in vitro cytotoxic activity of the synthesized compounds was studied in four different human carcinoma cell lines: HCT-15 (colon), HeLa (cervix-uterine), MCF-7 (breast) and PC-3 (prostate).