The crystal structures of α,ω-diaminoalkanecadmium(II) tetracyanonickelate(II)-aromatic molecule inclusion compounds. IV. (1,6-Diaminohexane)cadmium(II) tetracyanonickelate(II)-m-toluidine(1/1),-p-toluidine(1/1), and-2,4-xylidine(1/1) clathrates,and the coordination complex bis(p-toluidine) (1,6-diaminohexane)cadmium(II) tetracyanonickelate(II)

The crystal structures of the four title compounds have been analyzed by single crystal X-ray diffraction methods at room temperature. Three with a general formula Cd[NH₂(CH₂)₆NH₂]Ni(CN)₄·G (G=m-toluidine,Im;p-toluidine,Ip; and 2,4-xylidine,Ix) are the inclusion compounds of the respective aromatic molecules in the three-dimensional metal complex host (1,6-diaminohexane)cadmium(II) tetracyanonickelate(II). The remaining one is a coordination complex ofp-toluidine, bis(p-toluidine) (1,6-diaminohexane)cadmium(II) tetracyanonick-elate(II),II, Im, Ix, andII crystallize under similar experimental conditions;Ip is obtained using thep-toluidinemesitylene mixture at higher dilution than that used forII. Im crystallizes in the tri linic space group \(P\bar 1\) , witha=9.725(2),b=7.598(1),c=7.177(1) Å, α=90.44(1), β=98.80(1), γ=95.70(1)^o, andZ=1 (the final conventionalR=0.037 for 3526 reflections);Ip: monoclinic,P2/m,a=9.540(2),b=7.611(1),c=7.120(1) Å, β=100.95(1)^o, andZ=1 (R=0.027 for 1700 reflections);Ix: monoclinic,P2/m,a=9.628(2),b=7.613(1),c=7.122(1) Å, β=100.01(1)^o, andZ=1 (R=0.049 for 2704 reflections);II: monoclinic,P2₁/n,a=12.107(3),b=10.117(2),c=12.471(3) Å, β=113.67(2)^o, andZ=2 (R=0.037 for 2616 reflections). The structures ofIm, Ip andIx are similar to that of theo-toluidine inclusion compound of the same metal complex host. InII atrans pair of thep-toluidine molecules to the cadmium atom in the two-dimensional network formed by thecatena-μ-linkages of ?Cd?NH₂(CH₂)₆NH₂?Cd? and ?NC?Ni?CN?Cd?NC?Ni?CN?intersecting at each Cd atom; two cyanide groups of the tetracyanonickelate(II) moiety have free N-ends.     

Thermal studies on anisaldehyde carbohydrazone methyl trimethylammonium chloride complexes of zinc,cadmium and mercury

The kinetic parameters of the thermal decomposition of Zn, Cd and Hg(II) hydrazone complexes of the general formula [MCl₂(AGT)₂]Cl₂, where AGT=anisaldehyde carbohydrazone methyl trimethylammonium cation, $$CH_3 O - C_6 H_4 - CH = N - NH - CO - CH_2 - \mathop N\limits^ + (CH_3 )_3 ,$$ and M=Zn, Cd and Hg(II), have been determined from the corresponding thermal curves. The order of the reaction (n) and the activation energy (E _a) have been derived. The kinetic data are discussed in terms of the effect of the metal ion on the activation energy. A thermal decomposition mechanism is suggested.     

Kinetic parameters of thermal decomposition of anisaldehyde-girard T complexes of cobalt and copper bromides from TG and DSC data

The kinetic parameters relating to the thermal decompositions of the Co(II) and Cu(II) hydrazone complexes of general formula [ML₂Br₂]Cl₂, whereL = anisaldehyde-Girard T cation: CH₃OC₆H₄CH=N-NHCOCH₂= \(\mathop N\limits^ + \) (CH₃)₃, and M=Co(II) or Cu(II), were evaluated from TG and DSC data. The thermal stabilities of the cobalt and copper complexes are discussed.     

Photophysical Properties and Kinetic Studies of 2-Vinylpyridine-Based Cycloplatinated(II) Complexes Containing Various Phosphine Ligands

A series of cycloplatinated(II) complexes with general formula of [PtMe(Vpy)(PR₃)], Vpy = 2-vinylpyridine and PR₃ = PPh₃ (1a); PPh₂Me (1b); PPhMe₂ (1c), were synthesized and characterized by means of spectroscopic methods. These cycloplatinated(II) complexes were luminescent at room temperature in the yellow–orange region’s structured bands. The PPhMe₂ derivative was the strongest emissive among the complexes, and the complex with PPh₃ was the weakest one. Similar to many luminescent cycloplatinated(II) complexes, the emission was mainly localized on the Vpy cyclometalated ligand as the main chromophoric moiety. The present cycloplatinated(II) complexes were oxidatively reacted with MeI to yield the corresponding cycloplatinated(IV) complexes. The kinetic studies of the reaction point out to an S_N2 mechanism. The complex with PPhMe₂ ligand exhibited the fastest oxidative addition reaction due to the most electron-rich Pt(II) center in its structure, whereas the PPh₃ derivative showed the slowest one. Interestingly, for the PPhMe₂ analog, the trans isomer was stable and could be isolated as both kinetic and thermodynamic product, while the other two underwent trans to cis isomerization.     

Remarks on the determination of kinetic constants from thermogravimetric data

The methods for determining kinetic constants may have significant effects on the estimation results. The two-variable linear correlation method leads to values of the kinetic constants for which the difference between the calculated and measured values is comparable to or greater than the measurement precision. The non-linear method for calculating kinetic constants by searching for the minimum of the error function \(S1 = \sum\limits_{i = 1}^N {(m_{it} - m_i )^2 /N}\) , wherem _i andm _i are the measured and calculated values, respectively, andN is the number of experimental data, gives very precise results. A simple calculating technique is necessary for the fitting of the minimum point and the confidence region limit at the significance level. An appropriate calculation was made for metal oxidation according to the parabolic law.     

Mixed dimethyl sulfoxide-thiocarbamic ester complexes of platinum(II) halides

Summary The platinum(II) halidecis-[Pt(DMTC)(DMSO)X₂] andcis-[Pt(DETC)(DMSO)X₂](X=Cl or Br; DMSO=dimethyl sulfoxide; DMTC=EtOSCN-Me₂; DETC=EtOSCNEt₂) adducts and the platinum(II) and palladium(II) halide adducts,trans-[M(DETC)₂X₂] (M=Pt or Pd; X=Cl or Br), have been prepared. The complexes were characterized by i.r., and¹H and¹³Cn.m.r. spectroscopy. Both DMTC and DETC coordinate through the sulphur atoms. The 1:2 DETC complexes present the usualtrans configuration, whereas the presence of DMSO favourscis geometry in the mixed species.     

Analysis of dynamic kinetic data from solid-state reactions

The kinetics of heterogeneous reactions, involving one reactant in the solid phase, usually follow the lawα=K _∞ exp(?E/kT)f(1?α), where α is the degree of conversion of the solid, andK _∞ andE are the kinetic constants. A critical examination is given of the various methods which are currently used to analyse dynamic experimental data. The limitations of these methods and their insensitivity to the form off(1-α) are pointed out. An alternative approach free from these limitations is suggested. In this,f(1?α) is determined from isothermal experiments, and then the dynamic data are accurately analyzed to obtain the values of the kinetic constants. A case study is given to elucidate the applicability of the approach.     

Thermal decomposition reactions of nickel(II) complexes under quasi-equilibrium conditions

The stoichiometry of thermal decomposition and thermal (thermodynamic) stability was studied for the Werner clathrates [Ni(4-Mepy)₄(NCS)₂]·G, whereG = benzene(I), toluene(II) andp-xylene(III). The loss of the volatile components occurs in five steps in compounds I and II and in four steps in the complex III. According to the quasi-equilibrium data the thermodynamic stability of these compounds can be ordered in the following sequence: I<II<III. The increasing host-guest interaction (larger positive band shift in the visible spectra) was accompanied by increasing in the quasi-equilibrium temperature (T _D) for the complexes under study.     

Crystal structures ofcatena-[diligatocadmium(II) tetra-μ-cyanocadmate(II)] host clathrates: Diamminecadmium(II) tetracyanocadmate(II)-benzene(1/2), diamminecadmium(II) tetracyanocadmate(II)-aniline(1/2), ethylenediaminecadmium(II) tetracyanocadmate(II)-aniline(1/2), and a novel type bis(aniline)cadmium(II) tetracyanocadmate(II)-aniline(2/1)

The crystal structures of the four title clathrate compounds Cd(NH₃)₂Cd(CN)₄ · 2C₆H₆,I, Cd(NH₃)₂Cd(CN)₄ · 2C₆H₅NH₂,II, Cd(NH₂CH₂CH₂NH₂)Cd(CN)₄ · 2 C₆H₅NH₂,III, and Cd(C₆H₅NH₂)₂Cd(CN)₄ · 0.5C₆H₅NH₂,IV, have been analyzed by single crystal X-ray diffraction methods. CompoundI crystallizes in the monoclinic space groupC2/c,a = 12.063(2),b = 12.174(2),c = 14.621(1) Å,β = 90.976(9)°,Z = 4,R = 0.042 for 2388 reflections;II: monoclinic C₂/c,a = 12.1951(9),b = 12.078(1),c = 14.6921(7) Å,β = 93.436(5)°,Z = 4,R = 0.039 for 2374 reflections;III: monoclinicCc,a = 11.027(1),b = 12.0767(9),c = 15.837(1) Å,β = 92.059(9)°,Z = 4,R = 0.041 for 2883 reflections; andIV: monoclinicP2₁/n,a = 15.169(2),b = 16.019(2),c = 8.866(1) Å,β = 95.73(1)°,Z = 4,R = 0.052 for 3612 reflections. The three-dimensionalcatena-[diamminecadmium(II) tetra-μ-cyanocadmate(II)] hosts ofI andII are substantially isostructural to that of the already known Hofmann-Td-type Cd(NH₃)₂Hg(CN)₄ · 2C₆H₆. The three-dimensional en-Td-typecatena-[catena-μ-ethylenediaminecadmium(II) tetra-μ-cyanocadmate(II)] host ofIII, reinforced by the catena-μ-en linking between the octahedral Cd atoms, accommodates the aniline as the guest with a monoclinic distortion from the tetragonal symmetry of the previously reported en-Td-type benzene clathrate. InIV dual behavior of aniline, one as the unidentate ligand in the three-dimensional host and the other as the guest in the cage-like cavity, has been demonstrated.     

Synthesis and spectroscopic characterization of Zn(II), Cd(II), and Hg(II) ciprofloxacin complexes

Ciprofloxacin metal co mplexes with general for mula [M(CPF)₂]X₂·nH₂O [M = Zn(II), Cd(II), and Hg(II)] have been synthesised and characterized using elemental analysis (CHN), spectroscopic (UV-Vis, IR, MS, and ¹H NMR) and ther mogravimetric (TG and DTA) data. Using the Coats-Redfern and Horowitz-Metzeger methods, kinetic analysis of the thermogravimetric data had been performed.     

Kinetics of the thermal decomposition of ammonium thiocarbamate

Results of the kinetic study of the thermal decomposition of ammonium thiocarbamate in vacuum (ca. 10^?2 torr) in the temperature range 303–353 K are presented. Under these conditions ammonium thiocarbamate decomposes into gaseous products (NH₄COSNH₂→2 NH₃ + COS). Fifteen general equations for the kinetics of thermal decomposition of solids were taken into consideration. The following equation describes the experimental results over the whole range of the degree of decomposition: $$\alpha = \frac{{2k_2 }}{{ab}}(t - t_0 )[a + b - 2k_2 (t - t_0 )]$$ whereα=degree of decomposition,t=time,t ₀=time required to attain constant growth rate of nuclei, anda andb are the dimensions of the crystal. The temperature-dependence of the rate constantk ₂ was determined and the activation energy was found to be 10.7 kcal/mole. An experiment planning scheme was adopted in this study: in a series of experiments, each one was followed by statistical analysis in order to plan successive experiments depending on the results of the previous one.     

Synthesis and structural features of 1,3,2,5-dioxaboraphosphorinane complexes with Pt(II) and Pd(II) salts

Complexes of composition L₂MCl₂ [M=Pt, R=H (I), Me (II), Ph (III)], and LMC1₂ [M=Pd, R=H (IV)] are prepared by reaction of 4,6-R₂-2,5-diphenyl-1,3,2,5-dioxaboraphosphorinanes (L) with MCl₂. Far-IR and³¹P NMR spectroscopy are used to demonstrate that I is cis whereas II and III are trans complexes in the solid. The conformational behavior of I is studied by³¹P and¹H NMR. The asymmetric form of I exhibits anomalous stability.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2309–2312, October, 1991.     

Interaction of porphyrins with adenine and adenosine complexes. Effect of a metal nature

Reactions of complex formation of 5,10,15,20-tetraphenylporphine (H₂TPP) and tetra-tert-butylphthalocyanine (H₂(t-Bu)₄Pc) with adenine and adenosine complexes of d-metals in DMSO and ethanol are studied. It was found that H₂TPP reacts with Cu(II) and Hg(II) adeninates and adenosinates in DMSO, but does not react with Zn(II), Co(II), and Cd(II) adeninates and adenosinates (with both bridging and monodentate type of the ligand coordination). H₂(t-Bu)₄Pc enters the complex formation reaction with adeninates and adenosinates of all studied metals in DMSO at almost equal rates. The states of adenine and adenosine complexes of different d-metals in DMSO and ethanol are proposed on the basis of kinetic data obtained.     

Palladium(0) complexes coordinated with substituted olefins and tertiary phosphine ligands

New palladium(0) complexes with a variety of coordinated olefins [Pd(olefin)(PMePh₂)₂] (II) (olefin = styrene, ethyl methacrylate, methyl methacrylate, methyl acrylate, methacrylonitrile, and dimethyl maleate), were prepared by the reactions of [PdEt₂(PMePh₂)₂] (I) with corresponding olefins in toluene. These complexes were characterized by means of elemental analysis, IR and ¹H NMR spectroscopy and the chemical reactions. The dissociation of the coordinated olefin from complex II in solution was confirmed by spectroscopic studies of [Pd(mma)(PMePh₂)₂] (mma = methyl methacrylate). From the variable temperature NMR study, kinetic parameters for the dissociation process were determined as E_a = 7 kcal/mol, and ΔS³ (293 K) = -30 cal/deg · mol. Some new hydrido complexes, [Pd(H)ClL₂] (IV) (L = PMePh₂, PEtPh₂ and PEt₂Ph), were prepared by the reactions of [Pd(olefin)L₂] with dry HCl.     

Synthesis,characterization and thermal behaviour of adducts

The photoproduct of octacyanomolybdate(IV) and -tungstate(IV) with ethylenediamine and triethylenetetramine give complexes of the type K₃[Mo(O₂)(O)(OH)(C₉H₇ON)]·3C₉H₇ON I, K₂[W(O₂)(O) (C₉H₇ON)₃] II and K₃[Mo(CN)₃(OH)₄(C₉H₇ON)]·2C₉H₇ON·3H₂O III with 8-quinolinol (oxine). The IR spectra of the complex III shows the presence ofv(CN) peaks in the range 2047–2108 cm^?1 and oxine groupv(C-O) in the complex I, II and III in the range of 1100–1150 cm^?1. The lower region of IR spectra shows the M=O stretching while the higher thev(N-H) andv(OH). Thermal studies show the removal of uncoordinated water at 131?C from complex III. The decomposition of complexes I and II start from 150 and 212?C respectively. Oxine and cyano molecules were removed in stages at higher temperatures. The final product of the thermal decomposition was oxide which was of polymeric nature. The kinetic parameters viz. order of reaction ‘n’ and activation energy ‘E’ were determined by different methods.     

Thermal studies on trans-dichlorotetramminecobalt(III) complexes

Thermal studies have been carried out on trans-[Co(NH₃)₄Cl₂]X · YH₂O complexes (whereX=IO₃, BrO₃, NO₃, or NO₂ andY=0, 1, or 2) in an effort to find cases of trans to cis isomerization as occurs for the iodate. No evidence of isomerization was found for any of the other compounds. The complexes decompose in a series of steps and these reactions have been identified and kinetic parameters determined.     

Single-ion activities and Mn(Hg)/Mn(II) reactions in aqueous solutions of alkaline-earth chlorides

Combined thermodynamic and kinetic studies have yielded convenient single-ion activity coefficients for manganese(II), alkaline-earth, and chloride ions and standard exchange currents for the two steps of the Mn(Hg)/Mn(II) electrode in 0.005 M MnCl₂+0.495 M MeCl₂ (for Me=Mg, Ca, Sr, Ba, and Mn) at 25°C. The results indicate that the fall in mean ionic activity coefficient for the alkaline-earth chlorides along the sequence from magnesium to barium is carried to a larger extent by the cation than by the anion, that also the activity coefficient for the minority cation Mn(II) falls along this sequence, and that other than activity-coefficient effects on the Mn(Hg)/Mn(II) reactions appear only with barium ions, which retard the reactions additionally. The results are discussed with emphasis on ionic interactions and double-layer effects.     

Some transition metal complexes of new terdentate ligands: Bis[2-(diphenylphosphino)ethyl]benzylamine and bis[2-(diphenylarsino)ethyl)benzylamine

Complexes of the terdentate ligands bis[2-diphenylphosphino)ethyl]benzylamine (DPBA) and bis[2-(diphenylarsino)ethyl]benzylamine (DABA) with Co(II), Ni(II), Pd(II), Pt(II), Rh(III), Ir(III), Rh(I) and Ir(I) are reported. The ligand DPBA reacts with Co(II) ion to form two types of complexes: a high-spin, paramagnetic, tetrahedral Co(II) complex of composition [CoCl(DPBA)]Cl and a low-spin, paramagnetic, square-planar complex of composition [CoBr(DPBA)]B(C₆H₅)₄. The reaction of DPBA with Ni(II) ion in methanol yields low-spin, diamagnetic, square-planar complexes of type [NiX(DPBA)]Y [X = Cl, Br or I; Y = Cl or B(C₆H₅)₄]. Four-coordinate, square-planar, cationic complexes of type [MY(L⁺[M = Pd(II), Pt(II), Rh(I) or Ir(I); Y = Cl or P(C₆H₅)₃; L = DPBA or DABA], were obtained on reaction of L with various starting materials containing these metal ions. Reaction of DPBA and DABA with rhodium and iridium trichlorides gave octahedral, neutral complexes of general formula [MCl₃(L)] (M = Rh or Ir, L = DPBA or DABA). All the complexes were characterized on the basis of their elemental analysis, molarconductance data, magnetic susceptibilities, electronic spectra, IR spectral measurements, and¹H and³¹P-{¹H} NMR spectral data.     

Thermoanalytical study of some salts of3d metals withd-tartaric acid

The processes of dehydration and decomposition of the Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II) salts ofd-tartaric acid were studied by using TG, DTG and DTA methods in air or in argon, and also IR-spectroscopy. The equations of thermal decomposition were established. For the dehydration processes, the kinetic parametersn, E andInA were determined.     

Some aspects of the preparation,characterization and thermal decomposition of anisaldehyde Girard T complexes of some transition elements

Anisaldehyde Girard T complexes of Mn(II), Fe(III), Co(II) and Cu(II) with the general formula [MCl₂(AGT)₂]Cl₂ or [MCl₂(AGT)]Cl, where (AGT)=anisaldehyde carbohydrazone methyltrimethylammonium cation, H₃C-O-C₆H₄-CH=N-NHCOCH₂N⁺-(CH₃)₃ andM=Mn(II), Co(II), Fe(III) or Cu(II) were prepared. Elemental analysis, electrical conductance and IR spectra showed that the ligand coordinates with the studied metals in keto form through the azomethine and carbonyl groups. The molar conductances, electronic spectra and magnetic moments of the solid complexes were determined. The processes of thermal decomposition of these complexes were studied. From the analysis of the thermal decomposition curves obtained, the corresponding kinetic parametersn, E _a and logA were evaluated by two different methods and the effects of the central metal ions on the stabilities of the complexes are discussed.

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Zusammenfassung Es wurde die Herstellung und Isolierung von Anisaldehyd-G-T-Komplexen von Mn(II), Fe(III), Co(II) und Cu(II) der allgemeinen Formel [MCl₂(AGT)₂]Cl₂ oder [MCl₂(AGT)]Cl durchgeführt, wobei (AGT)=Anisaldehydcarbohydrazon-methyl-trimethyl-ammoniumkation H₃C-O-C₆H₄-CH=N-NHCOCH₂N⁺-(CH₃)₃ undM=Mn(II), Co(II), oder Fe(III) und Cu(II). Elementaranalyse, elektrische LeitfÄhigkeit und IR-Spektren zeigten, da\ der Ligand an den untersuchten Metallen in der Ketoform, über die Azomethin- und Carbonylgruppe koordiniert ist. Es wurden die molare LeitfÄhigkeit, Elektronenspektren und das magnetische Moment der festen Komplexe bestimmt. Der Vorgang der thermischen Zersetzung dieser Komplexe wurde untersucht. Durch Analyse der erhaltenen thermischen Zersetzungskurven wurden die entsprechenden kinetischen Parametern, E _a und logA durch zwei verschiedene Methoden ermittelt und weiterhin der Einflu\ des zentralen Metallions auf die StabilitÄt der Komplexe diskutiert.

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The authors would like to express their sincere thanks to Dr. F. I. M. Taha, Professor of Inorganic Chemistry and Head of the Chemistry Department, Faculty of Science, Mansoura University, for encouragement and useful discussions.