New paramagnets based on nanocarbon and cobalt(II)porphyrin: Magnetocaloric effect and specific heat capacity

Magnetocaloric Effect in Carbon-Containing Compounds

“…Recent studies [84] described below have shown the first experimental data about the existence of MCE in С 60 in the room temperature range associated with fullerene antiaromaticity. The aim of study [84] represented in this work was to confirm the magnetocaloric effect and obtain magnetocaloric parameters in the porphyrinfullerene conjugate built via axial donor-acceptor coordination of the pyridyl substituent in fullero [60]pyrrolidine with the central cobalt atom in the porphyrin complex. To achieve this, the authors directly determined the thermodynamic parameters of MCE and specific heat capacity of [60] fullerene (С 60 ), 1'-N-methyl-2'-(pyridine-4-yl) pyrrolidino[3′,4′:1,2][60]fullerene (PyC 60 ), 5,10,15,20-(tetra-4-tret-butylphenyl)21H, 23H-porphynato)cobalt(II) (Co II TBPP) and the triad (PyC 60 ) 2 Co II TBPP.…”

“…For example, metalloporphyrin-fullerene dyades collected through axial donor-acceptor coordination have been studied in the process of photo-induced electron transfer with acceptable parameters of photocurrent and IPCE [81][82][83]. Recent studies [84] described below have shown the first experimental data about the existence of MCE in С 60 in the room temperature range associated with fullerene antiaromaticity. The aim of study [84] represented in this work was to confirm the magnetocaloric effect and obtain magnetocaloric parameters in the porphyrinfullerene conjugate built via axial donor-acceptor coordination of the pyridyl substituent in fullero [60]pyrrolidine with the central cobalt atom in the porphyrin complex.…”

Recent progress in organometallic porphyrin‐based molecular materials for optical sensing, light conversion, and magnetic cooling

“…[167][168][169][170][171] A paramagnet heat capacity observed in the same experiment as for MCE values and calculated according to Equation (10 was evaluated as a difference (Equation (11). In the subsequent works, [34,166,[172][173][174][175][176][177] a new method based on using Equation (12 had allowed to eliminate the influence of a cell without a paramagnet and to determine the paramagnet true MCE. In the same time, the heat capacity of a paramagnet was independently observed by a direct differential scanning calorimetry method.…”

“…For the temperatures close to room, typical temperature dependencies are given in Figure 12 derived using the data of works. [173,174,178] The predominance of the electronic subsystem in magnetization is manifested in the absence of the MCE-C p correlation among structures of the same type, which is visible from the appearance of anomalies in the C p temperature dependencies for specific paramagnet as in the case of (AcO)GdPc or GdPc 2 [174] (Figure 12, Line 2).…”

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“…84 MeV is four and a half orders of 3.15s/0.07ms = 4.5•10 4 .Therefore, if the barrier height U b is greaterthan 3.26 MeV, then the reaction d + d → t + p +4.03 MeV prevails over the reaction d + d → 3 He + n +3.26. And the reaction d + d → 4 He + "Y" + 23.8 MeV becomes dominant, firstly, due to the huge energy release and, secondly, due to the absence of further decay of 4 He compound nucleus…”