Tetracyanocomplex clathrates and their changes caused by heating were studied. The intermediates formed were characterized
by IR and UV-VIS spectroscopy. Elemental analysis and XRD patterns were also used. For the visualisation of changes occurring
on the surface and the distribution of metallic elements therein were studied by electron microscopy and EDX. The extent of
the non-stoichiometric changes introduced by the topochemical course of the degradation reactions was correlated with the
measured electrical values.
clathrate systems: from 9.47 to 9.02 Å for the first stage FGICs (FGIC-1) with acetonitrile [ 1 ], from 10.03 to 9.61 Å for chloroform FGICs [ 2 ], from 10.28 to 9.80 Å with dichloroethane [ 3 ], from 9.82 to 9.32 Å for inclusioncompounds with methylene
Nifedipine complexes with β-cyclodextrin (β-CD), γ-cyclodextrin (γ-CD), 2-hydroxypropyl-β-cyclodextrin (2HP-β-CD), randomly
methylated-β-cyclodextrin (RM-β-CD) and heptakis(2,6-O-dimethyl)-β-cyclodextrin (DM-β-CD) have been prepared by both kneading and heating methods and their behaviour studied by
differential scanning calorimetry (DSC), diffuse reflectance mid-infrared spectroscopy (FTIR) and X-ray diffractometry (XRD).
DSC revealed the nifedipine melting endotherm with onset at approximately 171°C for the kneaded mixtures with β-CD, γ-CD and
2HP-β-CD, thus confirming the presence of nifedipine in the crystalline state, while some decrease in crystallinity was observed
in the DM-β-CD kneaded mixture. With RM-β-CD, however, broadening and shifting of the nifedipine endotherm and reduction in
its intensity suggested that the kneading could have produced an amorphous inclusion complex. These differing extents of interaction
of nifedipine with the cyclodextrins were confirmed by FTIR and XRD studies.
The decomposition of series of supramolecular compounds, namely inclusion compounds, was studied by means of different thermoanalytical
methods, i.e., traditional thermogravimetry, quasi-equilibrium thermogravimetry, and thermomechanical analysis. The series
of compounds included the intercalates on the base of fluorinated graphite C2F, the clathrates on the base of carbamide and on the base of coordination compounds and microporous inclusion compounds on
the base of coordination compounds. Kinetic parameters of decomposition processes were estimated within the approaches of
the non-isothermal kinetics (“model-free” kinetics, linear and non-linear regression methods for the topochemical equation
detection). The kinetic stability of the inclusion compounds under heating, the flexibility of the matrix structure, and the
thermodynamic stability of the intermediate phases are discussed.
Inclusion compounds (intercalates) of fluorinated graphite matrix with methylene dichloride (C2FxBrz·yCH2Cl2, x = 0.49, 0.69, 0.87, 0.92, z ≈ 0.01) were synthesized by guest substitution from acetonitrile to methylene dichloride. The kinetics of the thermal decomposition
(the first stage of filling → the second stage of filling) was studied under isothermal conditions at 291–303 K. The relationship
between the structure of host matrices with thermal properties and kinetic parameters of inclusion compounds is discussed.
Differential scanning calorimetry DSC has been applied to the analysis of drugcyclodextrin binary systems in order to gain experimental evidence of the interaction and determine the stoichiometry of the inclusion compound. Two model systems, paracetamolbetacyclodextrin and vinburnineg-ammacyclodextrin were tested through the comparison of thermal behaviors of interacted and non-interacted mixtures containing excess drug. DSC allowed a confirmation of both interaction and stoichiometry of the inclusion compounds.
The structures of the inclusion compounds formed by the host 9,9’-(ethyne-1,2-diyl)bis(fluoren-9-01) with pyridine and picolines are similar and display tubular topology. The host discriminates poorly between
these guests. The kinetics of desorption of the pyridine compound is governed by the Avrami-Erofe’ev equation A2, with an
activation energy of 111(7) kJ mol−1.
An earlier study of the interaction between solid urea and n-octane vapour in the presence of noncomplex-forming hydrocarbons by means of a vacuum microbalance technique revealed the
oscillatory nature of urea-octane inclusion compound (complex) formation: process damping, occurrence in the reverse direction
and repeated renewal without attainment of the complete saturation of the urea with octane.
The phenomenon is interpreted on the basis of the recently discovered oscillatory adsorption, regarded as the surface competition
between the spottily adsorbed A and B components, which results alternatively in spontaneous transitions from a state ‘A in
B’ to a state ‘B in A’ and vice versa, with simultaneous dramatic change in the spot configurations under A and B, as well as changes in the chemical potentials
of adsorbed A and B at the inversion points, certain minimal parts of the surface under A and B being permanently occupied
by each of the components. This latter signifies that the non-complex-forming hydrocarbon hinders the complete transition
of the urea to its inclusion compound phase.
The results of investigation of the influence of encapsulation on the mechanism of thermal decomposition of cyanide transition
metal complexes, based on data obtained by methods of differential thermal analysis (inert atmosphere) and thermodesorption
(mass-spectral monitoring of gaseous products) are represented. It was established, that encapsulation of cyanide iron(II)
and cobalt(III) complexes in faujasite type zeolite results in the hydrolytic mechanism of thermal destruction of complexes,
unlike to bulk analogues, which is determined by essential decreasing of the temperature of complex anions encapsulated destruction
beginning, up to temperatures while zeolite water molecules are saved; the gaseous products of thermal destruction composition
is determined by the peculiarities of localization of cations of different nature in inclusion compounds.