New Au(III), Pt(II) and Pd(II) complexes with glycyl-containing homopeptides

Twelve new Au(III), Pt(II) and Pd(II) complexes with glycyl-containing homopeptides glycyl-glycine (G2), glycyl-glycyl-glycine (G3), glycyl-glycyl-gycyl-glycine (G4), glycyl-glycyl-glycyl-glycyl-glycine (G5) and glycyl-glycyl-glycyl-glycyl-glycyl-glycine (G6) have been synthesized, isolated and characterized spectroscopically and structurally by means of solid-state linear-dichroic infrared (IR-LD) spectroscopy of oriented colloids in nematic liquid crystal host, ¹H- and ¹³C-NMR, TGA and DSC, UV–Vis spectroscopy, EPR, ESI- and FAB mass spectrometry and HPLC tandem mass spectrometry (HPLC-MS/MS). Quantum chemical calculations are carried out with a view to obtain the structures and spectroscopic properties of the ligand and newly synthesized metal complexes.     

Pt(II) complexes of 4-amino-4H-1,2,4-triazole

The coordination ability of 4-amino-4H-1,2,4-triazole with Pt(II), both in solution and solid states, is elucidated by conventional and linear-polarized IR spectroscopy of oriented colloid suspensions in nematic host, ¹H- and ¹³C-NMR, UV-Vis spectroscopy, mass spectrometry (ESI and FAB), TGV, and DSC methods. The interpretation of the spectroscopic characteristics of corresponding metal complexes is obtained by comparison with free 4-amino-4H-1,2,4-triazole. In addition, quantum chemical calculations of the last compound are performed to obtain data for electronic structures and optical properties of the ligand, thus supporting the experimental elucidation. The evaluation of the cell viability on a panel of human tumor cell lines is made. The new Pt(II) complexes exerted cytotoxic effects in a concentration-dependent manner.     

Reaction of dirhodium(II) tetraacetate with S-methyl-L-cysteine

Abstract

The reaction of antitumor active dirhodium(II) tetraacetate, [Rh₂(AcO)₄], with S-methyl-L-cysteine (HSMC) was studied at the pH of mixing (=4.8) in aqueous media at various temperatures under aerobic conditions. The results from UV–vis spectroscopy and electrospray ionization mass spectrometry (ESI–MS) showed that HSMC initially coordinates via its sulfur atom to the axial positions of the paddlewheel framework of the dirhodium(II) complex, and was confirmed by the crystal structure of [Rh₂(AcO)₄(HSMC)₂]. After some time (48?h at 25?°C), or at elevated temperature (40?°C), Rh-SMC chelate formation causes breakdown of the paddlewheel structure, generating the mononuclear Rh(III) complexes [Rh(SMC)₂]⁺, [Rh(AcO)(SMC)₂] and [Rh(SMC)₃], as indicated by ESI–MS. These aerobic reaction products of [Rh₂(AcO)₄] with HSMC have been compared with those of the two proteinogenic sulfur-containing amino acids methionine and cysteine. Comparison shows that the (S,N)-chelate ring size influences the stability of the [Rh₂(AcO)₄] paddlewheel cage structure and its Rh^II–Rh^II bond, when an amino acid with a thioether group coordinates to dirhodium(II) tetraacetate.     

The synthesis and characterization of three new vic -dioximes and their nickel(II), copper(II) and cobalt(II) complexes

Three new vic-dioximes, [L¹H₂], N-(4-ethylphenyl)amino-1-acetyl-1-cyclohexenylglyoxime, [L²H₂], N-(4-butylphenyl)amino-1-acetyl-1-cyclohexenylglyoxime, and [L³H₂], N-(4-methoxyphenyl)amino-1-acetyl-1-cyclohexenylglyoxime were synthesized from 1-acetyl-1-cyclohexeneglyoxime and the corresponding substituted aromatic amines. Metal complexes of these ligands were also synthesized with Ni(II), Cu(II), and Co(II) salts. These new compounds (ligands and complexes) were characterized with FT–IR, magnetic susceptibility measurement, molar conductivity measurements, mass spectrometry measurements, thermal methods (e.g. thermal gravimetric analysis), ¹H NMR (Nuclear Magnetic Resonance) and ¹³C NMR spectral data and elemental analyses.     

Copper(II) complexes with hydroxyl-containing dipeptides glycyl- L -serine and L -seryl- L -tyrosine

Dipeptides glycyl- _L -serine and _L -seryl– _L -tyrosine are tridentate ligands in coordination with Cu(II) through their NH₂?, N–(from deprotonated amide group) and O–atom (by COO- group), forming [Cu^II(LH_?1)H₂O]. The forth position of square-planar geometry of Cu²⁺ is occupied by H₂O as terminal ligand. Solid-state linear dichroic IR-spectroscopy, UV-Vis, mass spectrometry with ESI and FAB, tandem mass spectrometry (HPLC-MS/MS), TGV and DSC methods, EPR and magnetochemistry data prove the formation of five-membered chelate rings with participation of Cu²⁺ both in solution and in solid state.     

The Coordination Structure of the Extracted Cobalt(II) Complex with a Synergistic Mixture Containing Lix63 and Versatic10

In the present work, the cobalt(II ) synergist complex with isobutyric acid (HL^I ) and 5‐hydroxy‐4‐octanone oxime (HB^I ), which were the corresponding short‐chain analogs of active synergistic mixture of Versatic10 (HL ) and Lix63 (5,8‐diethyl‐7‐hydroxy‐6‐dodecanoneoxime, HB ), was prepared and studied by X‐ray single‐crystal diffraction. The crystal structure of the cobalt(II ) synergistic complex showed that the composition of the complex was Co(HB^I )₂(L^I )₂ with a cis‐form octahedron geometry structure. Both intra and intermolecular hydrogen bonding between the uncoordinated carbonyl oxygen atom of the deprotonated monodentate anionic ligand L^I and the hydrogen atom of the α‐hydroxy or the oxime hydroxyl group of HB^I were observed in the crystal lattice. In order to bridge the gap between the solid‐state structure of the cobalt(II ) synergist complex and the solution structure of the extracted cobalt(II ) complex with the actual synergistic mixture containing Versatic10 and Lix63 in the nonpolar organic phase, both the cobalt(II ) synergistic complex and the extracted cobalt(II ) complex were further investigated by Fourier transform infrared spectroscopy (FT‐IR ) and electrospray ionization mass spectrometry (ESI‐MS ). The results indicated that the extracted cobalt(II ) complex in the nonpolar organic phase might possess a similar coordination structure as that of the cobalt(II ) synergist complex.     

Silica gel surface modified with sulfanilamide for selective solid-phase extraction of Cu(II), Zn(II) and Ni(II)

A new chelating matrix has been prepared by immobilising sulfanilamide (SA) on silica gel (SG) surface modified with 3-chloropropyltrimethoxysilane as a sorbent for the solid-phase extraction (SPE) Cu(II), Zn(II) and Ni(II). The determination of metal ions in aqueous solutions was carried out by inductively coupled plasma optical emission spectrometry (ICP-OES). Experimental conditions for effective sorption of trace levels of Cu(II), Zn(II) and Ni(II) were optimised with respect to different experimental parameters using the batch and column procedures. The presence of common coexisting ions does not affect the sorption capacities. The maximum sorption capacity of the sorbent at optimum conditions was found to be 34.91, 19.07 and 23.62 mg g^?1 for Cu(II), Zn(II) and Ni(II), respectively. The detection limit of the method defined by IUPAC was found to be 1.60, 0.50 and 0.61 µg L^?1 for Cu(II), Zn(II) and Ni(II), respectively. The relative standard deviation (RSD) of the method under optimum conditions was 4.0% (n = 8). The method was applied to the recovery of Cu(II), Zn(II) and Ni(II) from the certified reference material (GBW 08301, river sediment) and to the simultaneous determination of these cations in different water samples with satisfactory results.     

ESI‐MS studies of palladium (II) complexes with 1‐(p‐toluenesulfonyl)cytosine/cytosinato ligands

The mononuclear complex Pd(1‐TosC‐N3)₂Cl₂ (2) containing 1‐(p‐toluenesulfonyl)cytosine (1) as a ligand, as well as dinuclear complexes Pd₂(1‐TosC^?‐N3,N4)₄ (3) and Pd₂(1‐TosC^?‐N3,N4)₂DMSO₂Cl₂ (4) containing the ligand anion (1‐TosC^?), was mass analyzed by electrospray ionization ion trap MS/MS and high resolution MS. Complexes 3 and 4 were obtained by recrystallization of 2 from DMF and DMSO, respectively. The behavior of complex 2 in different solutions was monitored by electrospray ionization mass spectrometry (ESI‐MS). Under the applied ESI‐MS conditions, complex 2 in methanol reorganized itself dominantly as new complex 3 and the solvent did not coordinate the formed species. In H₂O/DMSO, CH₃CN/DMSO and CH₃OH/DMSO solutions, complex 2 formed several new species with solvent molecules involved in their structure, e.g. complex 4 was formed as the major product. The newly formed species were also examined by LC‐MS‐DAD, confirming the solvent induced reorganization and the solution instability of complex 2. Copyright © 2009 John Wiley & Sons, Ltd.     

Thermal behavior of Cu(II)-, Cd(II)-, and Hg(II)-exchanged montmorillonite complexedwith cysteine

The thermal behavior of montmorillonite and organically modified montmorillonite, both treated with heavy metal cations [Cu(II), Cd(II) and Hg(II)], was characterized via thermal analyses (TG, DTG and DTA) combined with evolved species gas mass spectrometry (MS-EGA), and X-ray diffraction at in situ controlled temperature (HTXRD). The reactions involving Cu(II)- and Cd(II)-montmorillonite samples are mostly related to H₂O and OH loss, unlike Hg(II)-montmorillonite, where effects associated to Hg(II) loss are also present. Finally reactions related to dehydration, dehydroxylation and to organic matter decomposition can be observed in montmorillonite samples treated with cysteine.     

Synthesis,spectroscopic, and thermal analyses of trinuclear Mn(II), Co(II), Ni(II), and Zn(II) complexes with some sulfa derivatives

New bi- and trihomonuclear Mn(II), Co(II), Ni(II), and Zn(II) complexes with sulfa-guanidine Schiff bases have been synthesized for potential chemotherapeutic use. The complexes are characterized using elemental and thermal (TGA) analyses, mass spectra (MS), molar conductance, IR, ¹H-NMR, UV-Vis, and electron spin resonance (ESR) spectra as well as magnetic moment measurements. The low molar conductance values denote non-electrolytes. The thermal behavior of these chelates shows that the hydrated complexes lose water of hydration in the first step followed by loss of coordinated water followed immediately by decomposition of the anions and ligands in subsequent steps. IR and ¹H-NMR data reveal that ligands are coordinated to the metal ions by two or three bidentate centers via the enol form of the carbonyl C=O group, enolic sulfonamide S(O)OH, and the nitrogen of azomethine. The UV-Vis and ESR spectra as well as magnetic moment data reveal that formation of octahedral [Mn₂L¹(AcO)₂(H₂O)₆] (1), [Co₂(L¹)₂(H₂O)₈] (2), [Ni₂L¹(AcO)₂(H₂O)₆] (3), [Mn₃L²(AcO)₃(H₂O)₉] (5), [Co₃L²(AcO)₃(H₂O)₉] · 4H₂O (6), [Ni₃L²(AcO)₃(H₂O)₉] · 7H₂O (7), [Mn₃L³(AcO)₃(H₂O)₆] (9), [Co₂(HL³)₂(H₂O)₈] · 4H₂O (10), [Ni₃L³(AcO)₃(H₂O)₉] (11), [Mn₃L⁴(AcO)₃(H₂O)₉] · H₂O (13), [Co₂(HL⁴)₂(H₂O)₈] · 5H₂O (14), and [Ni₃L⁴(AcO)₃(H₂O)₉] (15) while [Zn₂L¹(AcO)₂(H₂O)₂] (4), [Zn₃L²(AcO)₃(H₂O)₃] · 2H₂O (8), [Zn₃L³(AcO)₃(H₂O)₃] · 3H₂O (12), and [Zn₃L⁴(AcO)₃(H₂O)₃] · 2H₂O (16) are tetrahedral. The electron spray ionization (ESI) MS of the complexes showed isotope ion peaks of [M]⁺ and fragments supporting the formulation.     

Synthesis and characterization of bis(organothiolato)mercury(ii) complexes by disproportionation of Hg2Cl2 in the presence of thiols

Mercury(I) chloride disproportionates to mercury metal and bis(organothiolato)mercury(II) in the presence of some thiols in good yields. The products were analyzed by means of ¹H?NMR and gas chromatographic–mass spectrometry (GC/MS), which indicated that the complexes are monomers in the gas phase and decomposed at elevated temperature to mercury(0) and corresponding disulfides.     

Assembly of Palladium(II) and Platinum(II) Metallo‐Rectangles with a Guanosine‐Substituted Terpyridine and Study of Their Interactions with Quadruplex DNA

Two novel [2+2] metallo‐assemblies based on a guanosine‐substituted terpyridine ligand ( 1 ) coordinated to palladium(II) ( 2 a ) and platinum(II) ( 2 b ) are reported. These supramolecular assemblies have been fully characterized by NMR spectroscopy, ESI mass spectrometry and elemental analyses. The palladium(II) complex ( 2 a ) has also been characterized by single crystal X‐ray diffraction studies confirming that the system is a [2+2] metallo‐rectangle in the solid state. The stabilities of these [2+2] assemblies in solution have been confirmed by DOSY studies as well as by variable temperature ¹H NMR spectroscopy. The ability of these dinuclear complexes to interact with quadruplex and duplex DNA was investigated by fluorescent intercalator displacement (FID) assays, fluorescence resonance energy transfer (FRET) melting studies, and electrospray mass spectrometry (ESI‐MS). These studies have shown that both these assemblies interact selectively with quadruplex DNA (human telomeric DNA and the G‐rich promoter region of c‐myc oncogene) over duplex DNA, and are able to induce dimerization of parallel G‐quadruplex structures.     

Cobalt(II), nickel(II), and copper(II) complexes of 14-membered hexaazamacrocycles: synthesis and characterization

Cobalt(II), nickel(II), and copper(II) complexes containing 5,12-di(4-bromophenyl)-7,14-dimethyl-1,2,4,8,9,11-hexaazacyclotetradeca-7,14-diene-3,10-dione (H₂L¹) and 5,12-diphenyl-7,14-dimethyl-1,2,4,8,9,11-hexaazacyclotetradeca-7,14-diene-3,10-dione (H₂L²) have been synthesized. All complexes were characterized by elemental analysis, MALDI TOF-MS spectrometry, and electronic absorption spectroscopy. The crystal structures of two compounds, [Cu₂(H₂L¹)Cl₄]_n and [NiL²], were determined by X-ray powder diffraction. In the polymeric [Cu₂(H₂L¹)Cl₄]_n, the Cu₂Cl₄ units and H₂L¹ molecules are situated on inversion centers. Each Cu(II) has a distorted trigonal-bipyramidal coordination environment formed by N and O from H₂L¹ [Cu–N 2.340(14)?Å, Cu–O 1.952(11)?Å], two bridging chlorides [Cu–Cl 2.332(5), 2.279(5)?Å] and one terminal chloride [Cu–Cl 2.320(6)?Å]. In the [NiL²] complex, the Ni(II) situated on inversion center has a distorted square-planar coordination environment formed by four nitrogens from L² [Ni–N 1.860(11), 1.900(11)?Å].     

Tandem mass spectroscopy as a tool for investigation of complexes of PNP‐lariat ether derivative with metal ions

The novel PNP‐lariat ether L with cyclotriphosphazene ring incorporated in the macrocyclic structure was synthesized and checked by the electrospray mass spectrometry (ESI‐MS) method for the ability to bind different types of ions Ag⁺, Ca²⁺, Cd²⁺, Cu²⁺, and Pb²⁺. Furthermore, the stability constants of the abovementioned ion complexes with the investigated ligand have been determined by direct and competitive potentiometric methods. To evaluate the stability of various complex types and to confirm the way of metal cation binding, the tandem mass spectra of the investigated ligand and its complexes were taken. As a result, we obtained quite a good relationship between the number and main types of complex species observed in ESI‐MS experiments and the forms of complexes for which the stabilization constants were determined by potentiometric methods. Moreover, we also concluded that in case of big discrepancies of stability constants, ESI‐MS experiments could provide information about the most stable form of the complexes, but they fail when the differences between the strength of the coordination binding are slightly different.     

Thermal, spectral and magnetic behaviour of 2,3,4-trimethoxybenzoates of Mn(II), Co(II), Ni(II) AND Cu(II)

Four new complexes of 2,3,4-trimethoxybenzoic acid anion with manganese(II), cobalt(II), nickel(II) and copper(II) cations were synthesized, analysed and characterized by standard chemical and physical methods. 2,3,4-Trimethoxybenzoates of Mn(II), Co(II), Ni(II) and Cu(II) are polycrystalline compounds with colours typical for M(II) ions. The carboxylate group in the anhydrous complexes of Mn(II), Co(II) and Ni(II) is monodentate and in that of Cu(II) monohydrate is bidentate bridging one. The anhydrous complexes of Mn(II), Co(II) and Ni(II) heated in air to 1273 K are stable up to 505–517 K. Next in the range of 505–1205 K they decompose to the following oxides: Mn₃O₄, CoO, NiO. The complex of Cu(II) is stable up to 390 K, and next in the range of 390–443 K it loses one molecule of water. The final product of its decomposition is CuO. The solubility in water at 293 K is of the order of 10^–3 mol dm^–3 for the Mn(II) complex and 10^–4 mol dm^–3 for Co(II), Ni(II) and Cu(II) complexes. The magnetic moment values of Mn²⁺, Co²⁺, Ni²⁺ and Cu²⁺ ions in 2,3,4-trimethoxybenzoates experimentally determined in the range of 77–300 K change from 5.64–6.57 μB (for Mn²⁺), 4.73–5.17 μB (for Co²⁺), 3.26–3.35 μB (for Ni²⁺) and 0.27–1.42 μB (for Cu²⁺). 2,3,4-Trimethoxybenzoates of Mn(II), Co(II) and Ni(II) follow the Curie–Weiss law, whereas that of Cu(II) forms a dimer.     

Mechanistic Insights into the Palladium(II)-catalyzed Intramolecular Cyclization of o-Alkynylphenylphosphonamide and N-(o-Alkynylphenyl)acetamide by Electrospray Ionization Mass Spectrometry

The intramolecular cyclization of o‐alkynylphenylphosphonamide and N‐(o‐alkynylphenyl)acetamide was monitored by electrospray ionization mass spectrometry (ESI‐MS) and its tandem version (ESI‐MS/MS). The proposed intermediates were successfully intercepted and characterized. In addition, the intermediates composed of the substrate coordinated to the palladium(II) center in the reaction of o‐alkynylphenylphosphonamide were unexpected before, and this interesting phenomenon of the substrate coordination seems associated with the unique structure of substrates.     

Thermal, spectral and magnetic characterization of Co(II), Ni(II) AND Cu(II) 4-chloro-2-nitrobenzoates

Physico-chemical properties of 4-chloro-2-nitrobenzoates of Co(II), Ni(II), and Cu(II) were studied. The complexes were obtained as mono- and trihydrates with a metal ion to ligand ratio of 1:2. All analysed 4-chloro-2-nitrobenzoates are polycrystalline compounds with colours depending on the central ions: pink for Co(II), green for Ni(II), and blue for Cu(II) complexes. Their thermal decomposition was studied only in the range of 293–523 K, because it was found that on heating in air above 523 K 4-chloro-2-nitrobenzoates decompose explosively. Hydrated complexes lose crystallization water molecules in one step and anhydrous compounds are formed. The final products of their decomposition are the oxides of the respective transition metals. From the results it appears that during dehydration process no transformation of nitro group to nitrite takes place. The solubilities of analysed complexes in water at 293 K are of the order of 10^–4–10^–2 mol dm^–3. The magnetic moment values of Co²⁺, Ni²⁺ and Cu²⁺ ions in 4-chloro-2-nitrobenzoates experimentally determined at 76–303 K change from 3.89 to 4.82 μ_B for Co(II) complex, from 2.25 to 2.98 μ_B for Ni(II) 4-chloro-2-nitrobenzoate, and from 0.27 to 1.44 μ_B for Cu(II) complex. 4-chloro-2-nitrobenzoates of Co(II), and Ni(II) follow the Curie–Weiss law. Complex of Cu(II) forms dimer.     

3-(Aryl)-2-sulfanylpropenoates of mercury(II) and phenylmercury(II)

Compounds [HQ]₂[Hg(L)₂] and [HQ][PhHg(L)] [where HQ = diisopropylammonium cation; L = pspa, fspa, tspa, where p = 3-(phenyl), f = 3-(2-furyl), t = 3-(2-thienyl), and spa = 2-sulfanylpropenoato] have been prepared by the reaction of mercury(II) acetate or phenylmercury(II) acetate with the corresponding acid in the presence of diisopropylamine in ethanol. The compounds have been characterized by elemental analysis, FAB mass spectrometry and IR and NMR (¹H, ¹³C) spectroscopy. The crystal structures of the [HQ]₂[Hg(L)₂] compounds show the presence of diisopropylammonium cations and [Hg(L)₂]²⁻ anions. In each anion the Hg atom is in an HgO₂S₂ environment and this can be described as nido-tbp. The crystal structures of the [HQ][PhHg(L)] compounds show the presence of diisopropylammonium cations and [PhHg(L)]⁻ anions in which the Hg atom adopts an HgCOS distorted T-environment. The NMR data suggest that the coordination mode of the ligand L²⁻ determined by X-ray diffractometry in the solid remains in solution.     

Development of a fast liquid chromatography/mass spectrometry screening method for angiotensin‐converting enzyme (ACE) inhibitors in complex natural mixtures like snake venom

A new robust high‐performance liquid chromatography/electrospray ionization mass spectrometry (HPLC/ESI‐MS)‐based screening method for angiotensin‐converting enzyme (ACE)‐inhibiting substances in crude samples is described. The ACE assay is carried out in a typical offline setup by incubation of the samples with ACE and angiotensin I (AI), followed by stopping the reaction with acetonitrile containing val⁵‐AI serving as internal standard (I.S.). AI and the product angiotensin II (AII) are extracted from the incubation mixture by turbulent‐flow chromatography (TFC) applied in backflush mode as online solid‐phase extraction and are directly quantified by ESI(+)‐MS. The presence of ACE inhibitors (ACEi) is detected by an increase in AI signal intensity and a corresponding decrease of AII signal, as compared to the blank assay. The overall time of analysis of the TFC/ESI‐MS method was 5 min, thus making the described setup suitable for a rapid screening method. The assay was validated using a known ACE inhibitor and the IC₅₀ values found were in good accordance with a common HPLC/UV method and literature data. The method was successfully applied for the screening of size‐exclusion chromatography fractions of the venom of the pitviper Bothrops moojeni. Three of 18 analyzed fractions inhibited ACE, due to peptides present as components of this snake venom. These compounds were extracted from the two most‐active fractions by means of TFC and isolated by means of HPLC. Three peptides with ACE inhibitory activity were characterized and their structures were elucidated with ESI‐MS/MS‐based de novo sequencing to be ZKWPPGKVPP, ZKWPRPGPEIPP and ZNWPRPGPEIPP, respectively (Z = pyroglutamic acid). Copyright © 2010 John Wiley & Sons, Ltd.     

Complexes of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) with 4-chloro-2-methoxybenzoic acid anion

The complexes of 4-chloro-2-methoxybenzoic acid anion with Mn²⁺, Co²⁺, Ni²⁺, Cu²⁺ and Zn²⁺ were obtained as polycrystalline solids with general formula M(C₈H₆ClO₃)₂·nH₂O and colours typical for M(II) ions (Mn – slightly pink, Co – pink, Ni – slightly green, Cu – turquoise and Zn – white). The results of elemental, thermal and spectral analyses suggest that compounds of Mn(II), Cu(II) and Zn(II) are tetrahydrates whereas those of Co(II) and Ni(II) are pentahydrates. The carboxylate groups in these complexes are monodentate. The hydrates of 4-chloro-2-methoxybenzoates of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) heated in air to 1273 K are dehydrated in one step in the range of 323–411 K and form anhydrous salts which next in the range of 433–1212 K are decomposed to the following oxides: Mn₃O₄, CoO, NiO and ZnO. The final products of decomposition of Cu(II) complex are CuO and Cu. The solubility value in water at 293 K for all complexes is in the order of 10^–3 mol dm^–3. The plots of χ_M vs. temperature of 4-chloro-2-methoxybenzoates of Mn(II), Co(II), Ni(II) and Cu(II) follow the Curie–Weiss law. The magnetic moment values of Mn²⁺, Co²⁺, Ni²⁺ and Cu²⁺ ions in these complexes were determined in the range of 76−303 K and they change from: 5.88–6.04 μ_B for Mn(C₈H₆ClO₃)₂·4H₂O, 3.96–4.75 μ_B for Co(C₈H₆ClO₃)₂·5H₂O, 2.32–3.02 μ_B for Ni(C₈H₆ClO₃)₂·5H₂O and 1.77–1.94 μ_B for Cu(C₈H₆ClO₃)₂·4H₂O.