ABSTRACT

The molar heat capacity (Cp) of solid uracil, its alkylated and halogenated derivatives, and cyclooligomethylenouracils in the temperature range of (298.15 to 343.15) K by a differential scanning calorimeter (SETARAM TG-DSC 111) were determined. It was demonstrated that the Cp value increases by increasing the number of methylene groups attached to the diketopyrimidine ring. The correlations Cp ) f(T) are given. The contributions of C-CH3, N-CH3, and C-NO2 groups as well as F, Cl, Br, and I atoms in the value of Cp for the temperature of 298.15 K are presented. The Chickos method for calculation of Cp values is discussed.

Compounds

#	Formula	Name
1	C4H4N2O2	2,4(1H,3H)-pyrimidinedione
2	C5H6N2O2	1-methyl-2,4(1H,3H)-pyrimidinedione
3	C5H6N2O2	uracil, 3-methyl-
4	C5H6N2O2	thymine
5	C5H6N2O2	2,4-dihydroxy-6-methylpyrimidine
6	C6H8N2O2	1,3-dimethyl-2,4-(1H,3H)-pyrimidinedione
7	C6H8N2O2	3,6-dimethyluracil
8	C6H8N2O2	1,6-dimethyluracil
9	C6H8N2O2	2,4-dihydroxy-5,6-dimethylpyrimidine
10	C7H10N2O2	1,3,6-trimethyl-2,4(1H,3H)-pyrimidinedione
11	C8H12N2O2	2,4(1H,3H)-pyrimidinedione, 1,3,5,6-tetramethyl-
12	C8H12N2O2	2,4(1H,3H)-pyrimidinedione, 5-ethyl-1,3-dimethyl-
13	C9H14N2O2	2,4(1H,3H)-pyrimidinedione, 1,3-dimethyl-5-propyl-
14	C9H14N2O2	2,4(1H,3H)-pyrimidinedione, 1,3-dimethyl-6-propyl-
15	C11H16N2O2	1H-cycloheptapyrimidine-2,4(3H,5H)-dione, 6,7,8,9-tetrahydro-1,3-dimethyl-
16	C4H3ClN2O2	6-chlorouracil
17	C4H3FN2O2	5-fluoro-2,4(1H,3H)-pyrimidinedione
18	C4H3ClN2O2	5-chloro-2,4-pyrimidinedione
19	C4H3IN2O2	5-iodouracil
20	C4H3N3O4	2,4-pyrimidinedione, 5-nitro-
21	C8H12N2O2	2,4(1H,3H)-pyrimidinedione, 6-ethyl-1,3-dimethyl-
22	C10H16N2O2	2,4(1H,3H)-pyrimidinedione, 5-butyl-1,3-dimethyl-
23	C10H16N2O2	2,4(1H,3H)-pyrimidinedione, 6-butyl-1,3-dimethyl-
24	C4H3BrN2O2	5-bromouracil
25	C5H3F3N2O2	5-(trifluoromethyl)uracil
26	C6H8N2O2	1,5-dimethyluracil
27	C9H12N2O2	1,3-dimethyl-5,6-trimethyleneuracil
28	C10H14N2O2	1,3-dimethyl-5,6,7,8-tetrahydroquinazoline-2,4(1H,3H)-dione

Datasets

The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type	Compound-#	Property	Variable	Constraint	Phase	Method	#Points
POMD	1	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	SDSC:UFactor:2	10
POMD	2	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	SDSC:UFactor:2	10
POMD	3	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	SDSC:UFactor:2	10
POMD	4	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	SDSC:UFactor:2	10
POMD	5	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	SDSC:UFactor:2	10
POMD	6	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	SDSC:UFactor:2	10
POMD	7	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	SDSC:UFactor:2	10
POMD	8	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	SDSC:UFactor:2	10
POMD	9	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	SDSC:UFactor:2	10
POMD	10	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	SDSC:UFactor:2	10
POMD	11	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	SDSC:UFactor:2	10
POMD	12	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	SDSC:UFactor:2	10
POMD	13	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	SDSC:UFactor:2	6
POMD	14	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	SDSC:UFactor:2	6
POMD	15	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	SDSC:UFactor:2	10
POMD	16	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	SDSC:UFactor:2	10
POMD	17	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	SDSC:UFactor:2	10
POMD	18	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	SDSC:UFactor:2	10
POMD	19	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	SDSC:UFactor:2	10
POMD	20	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	SDSC:UFactor:2	10
POMD	21	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	SDSC:UFactor:2	6
POMD	22	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	SDSC:UFactor:2	2
POMD	23	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	SDSC:UFactor:2	6
POMD	24	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	SDSC:UFactor:2	10
POMD	25	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	SDSC:UFactor:2	10
POMD	26	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	SDSC:UFactor:2	10
POMD	27	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	SDSC:UFactor:2	3
POMD	28	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	SDSC:UFactor:2	6

Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

Heat Capacities of Uracil, Thymine, and Its Alkylated, Cyclooligomethylenated, and Halogenated Derivatives by Differential Calorimetry

Zielenkiewicz, W.[Wojciech], Kozbial, M.[Malgorzata], Swierzewski, R.[Rafal], Szterner, P.[Piotr]

ABSTRACT