New soluble fullerene derivatives But n C60 were synthesized by the reaction of C60M n (THF) x (M = Li, Na; n = 4, 6, 8, 10, 12) with tert-butyl bromide ButBr. The thus obtained compounds were characterized by spectroscopic methods (IR and NMR spectroscopy), mass spectrometry (MALDI), elemental analysis, and quantum chemical calculations. HPLC was used for chromatographic separation of the products of the reaction of C60Na n (THF) x (n = 4, 6, 8, 12) with ButBr. It was found that But 4C60 and But 6C60 decompose on the column. A complex of physicochemical methods of analysis was used for establishing compositions of individual fractions of chromatographic separation of But 4C60. The structure of one of the components was determined as 1-tert-butyl-1,2-dihydrofullerene 1,2-ButC60H.

Low-temperature heat capacities of the crystalline fullerene complex ((CH3)(3)Si)(12)C-60 have been measured by a precision adiabatic calorimeter over the temperature range from T = (6.5 to 350) K for the first time. The experimental results have been used to calculate the standard (p degrees = 0.1 MPa) thermodynamic functions: molar heat capacities, C-p,m(0), enthalpy, H degrees(T) - H degrees(0), entropy, S degrees(T), and Gibbs energy, G degrees(T) - H degrees(0), of ((CH3)(3)Si)(12)C-60(cr) over the range from T --> 0 K to T = 350 K. The low-temperature (T < 50 K) dependence of the heat capacity was analyzed on the basis of Debye's heat capacity theory of solids and its fractal variant. Following that analysis, the characteristic temperatures as well as the fractal dimension were determined, and some conclusions about the structure topology were made. The standard entropy of format,ion at T = 298.15 K of ((CH3)(3)Si)(12)C-60(cr) was calculated. The standard thermodynamic properties of tested fullerene complex and previously Studied C-60 fullerite/fullerene complex (t-Bu)(12)C-60 were compared.

Low-temperature heat capacities of the crystalline coordination compound Li12C60(THF)(1.4) have been measured by a precision adiabatic calorimeter over the temperature range T = 6 K to T = 350 K and by a differential scanning calorimeter over the temperature range T = 330 K to T = 520 K for the first time. Using the obtained data, the temperature of the onset of Li12C60(THF)(1.4) destruction was determined to be 468 K. The experimental results have been used to calculate the standard (p degrees = 0.1 MPa) thermodynamic functions: molar heat capacities C-p,C-m degrees, enthalpy H degrees(T) - H degrees(0), entropy S degrees(T), and Gibbs energy G degrees(T) - H degrees(0) of Li12C60(THF)(1.4) (cr) over the range from T--> 0 K to T = 468 K. The low-temperature (T < 50 K) dependence of the heat capacity was analyzed based on Debye's heat capacity theory of solids and its fractal variant. As results, the characteristic temperatures as well as the fractal dimension were determined, and some conclusions about structure topology are given. The standard entropy of formation at T = 298.15 K of Li12C60(THF)(1.4) (cr) was calculated. The standard thermodynamic properties of tested fulleride and previously studied C-60 fullerite and hydrofullerene C60H36 were compared.

The temperature dependence of heat capacity C p o = f ( T ) of fullerene derivative ( t -Bu) 12 C 60 has been measured by a adiabatic vacuum calorimeter over the temperature range T = 6–350 K and by a differential scanning calorimeter over the temperature range T = 330–420 K for the first time. The low-temperature ( T ≤ 50 K) dependence of the heat capacity was analyzed based on Debye’s the heat capacity theory of solids and its fractal variant. As a consequence, the conclusion about structure heterodynamicity is given. The experimental results have been used to calculate the standard thermodynamic functions C p o ( T ), H o ( T )− H o (0), S o ( T ) and G o ( T ) − H o (0) over the range from T → 0 to 420 K. The standard entropy of formation at 298.15 K of fullerene derivative under study was calculated. The temperature of decomposition onset of derivative was determined by differential scanning calorimetery and thermogravimetric analysis. The standard thermodynamic characteristics of ( t -Bu) 12 C 60 and C 60 fullerite were compared.

The temperature dependence of heat capacity C (p) (o) = f(T) of fullerene derivative (t-Bu)(12)C-60 has been measured by a adiabatic vacuum calorimeter over the temperature range T = 6-350 K and by a differential scanning calorimeter over the temperature range T = 330-420 K for the first time. The low-temperature (T a parts per thousand currency sign 50 K) dependence of the heat capacity was analyzed based on Debye's the heat capacity theory of solids and its fractal variant. As a consequence, the conclusion about structure heterodynamicity is given. The experimental results have been used to calculate the standard thermodynamic functions C (p) (o) (T), H (o)(T)-H (o)(0), S (o)(T) and G (o)(T) - H (o)(0) over the range from T -> 0 to 420 K. The standard entropy of formation at 298.15 K of fullerene derivative under study was calculated. The temperature of decomposition onset of derivative was determined by differential scanning calorimetery and thermogravimetric analysis. The standard thermodynamic characteristics of (t-Bu)(12)C-60 and C-60 fullerite were compared.

Low-temperature heat capacities of the crystalline fullerene complex ((CH3)3Si)12C60 have been measured by a precision adiabatic calorimeter over the temperature range from T = (6.5 to 350) K for the first time. The experimental results have been used to calculate the standard (po = 0.1 MPa) thermodynamic functions: molar heat capacities, Cp,mo, enthalpy, Ho(T) − Ho(0), entropy, So(T), and Gibbs energy, Go(T) − Ho(0), of ((CH3)3Si)12C60(cr) over the range from T → 0 K to T = 350 K. The low-temperature (T < 50 K) dependence of the heat capacity was analyzed on the basis of Debye's heat capacity theory of solids and its fractal variant. Following that analysis, the characteristic temperatures as well as the fractal dimension were determined, and some conclusions about the structure topology were made. The standard entropy of formation at T = 298.15 K of ((CH3)3Si)12C60(cr) was calculated. The standard thermodynamic properties of tested fullerene complex and previously studied C60 fullerite/fullerene complex (t-Bu)12C60 were compared.

The temperature dependence of the heat capacity C p o of the [(Me3Si)7C60]2 fullerene complex was measured for the first time using precision adiabatic vacuum calorimetry over the temperature range 6.7–340 K and high-accuracy differential scanning calorimetry at 320–635 K. For the most part, the error in the C p o values was about ±0.5%. An irreversible endothermic effect caused by the splitting of the dimeric bond between fullerene fragments and the thermal decomposition of the complex was observed at 448–570 K. The thermodynamic characteristics of this transformation were calculated and analyzed. Multifractal analysis of the low-temperature (T < 50 K) heat capacity was performed, and conclusions were drawn concerning the character of the heterodynamicity of the structure. The experimental data obtained were used to calculate the standard thermodynamic functions C p o (T), H o (T) − H o (0), S o (T) − S o (0), and G o (T) − H o (0) over the temperature range from T → 0 to 445 K and estimate the standard entropy of formation of the compound from simple substances at 298.15 K. The standard thermodynamic properties of [(Me3Si)7C60]2 are compared with those of the (C60)2 dimer, the [(η6-Ph2)2Cr]+[C60]•̄ fulleride, and the initial C60 fullerene.

In the present work, firstly the temperature dependence of heat capacity Cp,m∘=f(T) of the crystalline fullerene complex [(Me3Si)3C60]2 has been measured between T=(6 and 350)K and T=(330 and 480)K by precision adiabatic vacuum and dynamic calorimetry, respectively. The irreversible endothermic effect was detected in the temperature range from T=(400 to 466)K and its thermodynamic characteristics have been determined and analysed. This transformation was caused by the opening of a dimeric bond between fullerene fragments and the decomposition of the tested complex on heating. The experimental data were used for calculating the standard (p∘=0.1MPa) thermodynamic functions Cp,m∘/R, Δ0THm∘/RT, Δ0TSm∘/R and Φm∘/R=Δ0TSm∘/R-Δ0THm∘/RT (where R is gas constant) in the range 0 ⩽T/K⩽400. The value of the standard entropy of formation of the complex from simple substances at T=298.15K has been estimated.

Soluble dimer compounds of the general formula [C 60 ( Me 3 Si) n ] 2 (where n = 3, 5, 7, or 9 and M e = CH 3 ) and a soluble monomer compound, C 60 ( Me 3 Si) 12 , are synthesized by the reaction of the compound C 60 Na n ( THF ) x (where n = 4, 6, 8, 10, or 12 and THF = tetrahydrofuran) with trimethylchlorosilane Me 3 SiCl. The compounds synthesized are identified using IR and NMR spectroscopy and mass spectrometry. An irreversible endothermic effect exhibited by the [C 60 ( Me 3 Si) 7 ] 2 compound in the temperature range 448–570 K is revealed by dynamic adiabatic calorimetry. From analyzing the experimental results, it becomes possible for the first time to demonstrate the structural flexibility of the fullerene in the following sequence of reactions: [ C_60C_60 Na_12C_60 (Me_3 Si)_12[C_60 H_n ]C_60; C_60C_60 Na_8 [C_60 (Me_3 Si)_7 ]_2 [ products of the; transformation of +; Me_3 Si groups; ] C_60^ -; ]

Two-color photoionization of nickelocene molecules cooled in a supersonic jet is performed using a tunable nanosecond pulsed laser. The first stage of the multiphoton excitation is the transition from the highest occupied molecular orbital of nickelocene to the lowest Rydberg level. Conditions are found under which molecular ions (η 5 -C 5 H 5 ) 2 Ni + are the only product of the multiphoton ionization in the one-color experiment. Irradiation of an excited molecule by an intense pulse of another laser increases significantly the yield of molecular ions. The dependence of the yield of (η 5 -C 5 H 5 ) 2 Ni + ions on the frequency of the second laser makes it possible to determine the adiabatic ionization potential of nickelocene as 6.138±0.012eV.

A modified method is proposed for preparing fullerene compounds with alkali metals in a solution. The compounds synthesized have the general formula Me n C60(THF)x, where Me = Li or Na; n=1–4, 6, 8, or 12; and THF = tetrahydrofuran. The use of preliminarily synthesized additives MeC10H8 makes it possible to prepare fullerene compounds with an exact stoichiometric ratio between C 60 n− and Me+. The IR and EPR spectra of the compounds prepared are analyzed and compared with the spectra of their analogs available in the literature. The intramolecular modes T u (1)-T u (4) for the C 60 n− anion are assigned. The splitting of the T u (1) mode into a doublet at room temperature for Me n C60(THF)x (n=1, 2, 4) compounds indicates that the fullerene anion has a distorted structure. An increase in the intensity of the T u (2) mode, a noticeable shift of the T u (4) mode toward the long-wavelength range, and an anomalous increase in the intensity of the latter mode for the Li3C60(THF)x complex suggest that, in the fullerene anion, the coupling of vibrational modes occurs through the charge-phonon mechanism. The measured EPR spectra of lithium-and sodium-containing fullerene compounds are characteristic of C 60 − anions. The g factors for these compounds are almost identical and do not depend on temperature. The g factor for the C 60 n− anion depends on the nature of the metal and differs from the g factor for the C 60 − anion.

Two-photon ionization of the nickelocene molecules cooled in a supersonic jet was performed for the first time by simultaneous excitation of (η 5 −C 5 H 5 )2Ni with two tunable nano- second dye lasers. The one-photon transition from the HOMO to the Rydberg R4p level was used as the initial step of the multiphoton excitation. In a one-color experiment, the conditions were found for generation of the intact molecular ion, (η 5 −C 5 H 5 )2Ni + , as the only ionic product of the multiphoton ionization. The use of an intense pulse of the second dye laser lead to an increase in the yield of the molecular ion.

Efficient multiphoton ionization of nickelocene molecules in a supersonically cooled molecular beam has been performed for the first time with a nanosecond tunable dye laser operating in the 35,000-cm−1 region which corresponds to the lowest Rydberg transition observed in the one-photon absorption spectrum. The time-of-flight mass spectra obtained show strong signals of intact molecular ions Cp2Ni+ (Cp=η5-C5H5) and weaker peaks of fragment ions CpNi+. The conditions have been found for generation of Cp2Ni+ as the only ionic product of multiphoton excitation. The ion signal dependence on the laser intensity and the resonance-enhanced multiphoton ionization spectrum measured at the mass of Cp2Ni+ testify for saturation of absorption and/or ionization steps at the laser pulse intensities used (2–6 MW cm−2). Possible mechanisms of multiphoton processes resulting in formation of the ions observed are discussed.

AbstractDurch Umsetzung von Dicyclopentadienyl‐nickel (I) mit Bis‐triphenylgerrnyl‐cadmium (II) in Toluol entsteht die Cadmiumverbindung (III).