TY - JOUR

T1 - Thermal behavior of volatile palladium(II) complexes with tetradentate Schiff bases containing propylene-diimine bridge

AU - Vikulova, Evgeniia S.

AU - Cherkasov, Sergey A.

AU - Nikolaeva, Nataliya S.

AU - Smolentsev, Anton I.

AU - Sysoev, Sergey V.

AU - Morozova, Natalya B.

PY - 2019/2/28

Y1 - 2019/2/28

N2 - Palladium(II) complexes with tetradentate Schiff bases, Pd(acacpda)(I) and Pd(acacdmpda)(II) (acacpda2−—N,N′-(propylene)-bis(acetylacetoneiminato-), acacdmpda2−—N,N′-(2,2-dimethylpropylene)-bis(acetylacetoneiminato-)), have been synthesized, purified and characterized by elemental analysis, IR and NMR spectroscopy. Complex I was obtained for the first time, and its solid-state structure was investigated by single-crystal X-ray diffraction. It has a discrete molecular structure with the Pd2+ ion being in a distorted square-planar coordination environment formed by N and O atoms of the acacpda2− ligand. The thermal properties of complexes I and II in condensed phase were investigated by thermogravimetry. Compound II transfers into the gas phase almost completely, while compound I evaporates with a partial decomposition. The temperature dependences of saturated vapor pressure were measured by the flow method in the temperature intervals (423–457) and (422–478) K for I and II, respectively. Both complexes were shown to exhibit an excellent stability upon sublimation. The thermodynamic parameters of sublimation processes were calculated to be: ΔsubH440 = (133 ± 4) kJ mol−1, ΔsubS440 0= (210 ± 9) J (mol K)−1 for I, ΔsubH450 = (135 ± 1) kJ mol−1, ΔsubS450 0= (218 ± 3) J (mol K)−1 for II. It has been found that the complex II with a more bulky Schiff base ligand possesses slightly higher vapor pressure values as compared to I, which is probably due to the lower contribution of weak intermolecular interactions occurring in the crystal structure of II.

AB - Palladium(II) complexes with tetradentate Schiff bases, Pd(acacpda)(I) and Pd(acacdmpda)(II) (acacpda2−—N,N′-(propylene)-bis(acetylacetoneiminato-), acacdmpda2−—N,N′-(2,2-dimethylpropylene)-bis(acetylacetoneiminato-)), have been synthesized, purified and characterized by elemental analysis, IR and NMR spectroscopy. Complex I was obtained for the first time, and its solid-state structure was investigated by single-crystal X-ray diffraction. It has a discrete molecular structure with the Pd2+ ion being in a distorted square-planar coordination environment formed by N and O atoms of the acacpda2− ligand. The thermal properties of complexes I and II in condensed phase were investigated by thermogravimetry. Compound II transfers into the gas phase almost completely, while compound I evaporates with a partial decomposition. The temperature dependences of saturated vapor pressure were measured by the flow method in the temperature intervals (423–457) and (422–478) K for I and II, respectively. Both complexes were shown to exhibit an excellent stability upon sublimation. The thermodynamic parameters of sublimation processes were calculated to be: ΔsubH440 = (133 ± 4) kJ mol−1, ΔsubS440 0= (210 ± 9) J (mol K)−1 for I, ΔsubH450 = (135 ± 1) kJ mol−1, ΔsubS450 0= (218 ± 3) J (mol K)−1 for II. It has been found that the complex II with a more bulky Schiff base ligand possesses slightly higher vapor pressure values as compared to I, which is probably due to the lower contribution of weak intermolecular interactions occurring in the crystal structure of II.

KW - Crystal structure

KW - MOCVD precursors

KW - Palladium(II) complexes

KW - Schiff bases

KW - Vapor pressure

KW - CHEMICAL-VAPOR-DEPOSITION

KW - CRYSTAL-LATTICE ENERGY

KW - MEMBRANES

KW - NOBLE-METALS

KW - NANOSTRUCTURES

KW - BETA

KW - HYDROGEN

KW - ALLOY-FILMS

KW - PD

KW - ATOMIC LAYER DEPOSITION

UR - http://www.scopus.com/inward/record.url?scp=85047164965&partnerID=8YFLogxK

U2 - 10.1007/s10973-018-7371-z

DO - 10.1007/s10973-018-7371-z

M3 - Article

AN - SCOPUS:85047164965

VL - 135

SP - 2573

EP - 2582

JO - Journal of Thermal Analysis and Calorimetry

JF - Journal of Thermal Analysis and Calorimetry

SN - 1388-6150

IS - 4

ER -