Limits of isomorphous substitution of CnH2n + 2 chains in paraffins as a function of temperature
Abstract
Synthetic solid solutions of n-paraffins C23H48 and C21H44 have been studied by the thermoroentgenographic method. It is shown that the limits of isomorphous substitutions of molecules in these paraffins with molecular ratios C23:C21 = 1:2, 1:1 and 2:1 are temperature dependent. At rising temperatures all solid solutions first break down to form two phases which coexist in a narrow temperature range (3 – 5°C) and then become homogeneous at further elevation of temperature. Isomorphism in the system is established to be violated in the course of intensive structural rearrangements; it gets restored shortly (7 – 9°C) before the orthorhombichexagonal polymorphic transformation. A decrease in the limits of isomorphous substitutions which occurs at rising temperatures is explained by differences in energy states of paraffin chains having different lengths: relatively long chains oscillate about their own axes whereas shorter chains perform complete rotations and get “separated” from solid solutions.
Artikel in diesem Heft
- Limits of isomorphous substitution of CnH2n + 2 chains in paraffins as a function of temperature
- Crystal structure analysis from powder diffraction data
- Intensitätsstatistik für Strukturen mit Überstruktureffekten
- Crystal and molecular structure of 10-methoxy-8, 8-dimethyl 2H,8H-benzo (1,2-b:5,4-b′-dipyron-2-one) (Luvangetin)
- Crystal structure of a complex of glycine with zinc chloride
- Ratio image seeking with multiple-wavelength X-ray diffraction data
- Verfeinerung der Kristallstruktur von Anthophyllit vom Ochsenkogel/Gleinalpe, Österreich
- Präzisionsbestimmung des Skalierungsfaktors für Relativwerte von Strukturamplituden mit Messung von Absolutintensitäten an Pulverpräparaten
- The X-ray revised stereochemistry of the hydroperoxide of atractyligenin
- Crystal structures of N-benzylcarbonyl-α-aminoisobutyric acid mono- and tripeptide methyl ester derivatives
- The crystal structure of U4Ni5Al18
- The crystal structure of Cs2Nd(N3)5
- The crystal structure of Tl5Te3 and its relationship to the Cr5B3 type
- A phosphorous ylide with a secondary P…O bond. The crystal structure of a-[6-furazano][3,4-b]-quinoxalinyl-a-carbethoxymethylenetriphenylphosphorane(butene-2,3,4-dimethylhexene-3)solvate
- New data for 2-thiophenecarboxylic acid
- Elastic and thermoelastic properties of twelve adducts of betaine, (CH3)3NCH2COO, with H2O, HCl, HBr, HI, HNO3, H2SO4, H3PO3, H3PO4, 1,4-toluene sulfonic acid, MnCl2 and KBr
Artikel in diesem Heft
- Limits of isomorphous substitution of CnH2n + 2 chains in paraffins as a function of temperature
- Crystal structure analysis from powder diffraction data
- Intensitätsstatistik für Strukturen mit Überstruktureffekten
- Crystal and molecular structure of 10-methoxy-8, 8-dimethyl 2H,8H-benzo (1,2-b:5,4-b′-dipyron-2-one) (Luvangetin)
- Crystal structure of a complex of glycine with zinc chloride
- Ratio image seeking with multiple-wavelength X-ray diffraction data
- Verfeinerung der Kristallstruktur von Anthophyllit vom Ochsenkogel/Gleinalpe, Österreich
- Präzisionsbestimmung des Skalierungsfaktors für Relativwerte von Strukturamplituden mit Messung von Absolutintensitäten an Pulverpräparaten
- The X-ray revised stereochemistry of the hydroperoxide of atractyligenin
- Crystal structures of N-benzylcarbonyl-α-aminoisobutyric acid mono- and tripeptide methyl ester derivatives
- The crystal structure of U4Ni5Al18
- The crystal structure of Cs2Nd(N3)5
- The crystal structure of Tl5Te3 and its relationship to the Cr5B3 type
- A phosphorous ylide with a secondary P…O bond. The crystal structure of a-[6-furazano][3,4-b]-quinoxalinyl-a-carbethoxymethylenetriphenylphosphorane(butene-2,3,4-dimethylhexene-3)solvate
- New data for 2-thiophenecarboxylic acid
- Elastic and thermoelastic properties of twelve adducts of betaine, (CH3)3NCH2COO, with H2O, HCl, HBr, HI, HNO3, H2SO4, H3PO3, H3PO4, 1,4-toluene sulfonic acid, MnCl2 and KBr
