The Following Improvements Have Been Made in the Manuscript

The following improvements have been made in the manuscript:

Abstract

The first sentence:

incorrect:Thermal behaviour of novel zinc(II) benzoate complex compounds with caffeine and urea, namely …

correct:Thermal behaviours of three zinc(II) benzoate complex compounds (two new with caffeine and urea), namely Zn(C6H5COO)2, Zn(C6H5COO)2·caf2, Zn(C6H5COO)2∙u2, were characterized by using Thermogravimetry (TG/DTG), Differential Thermal Analysis (DTA), Evolved Gas Analysis (EGA) with Mass Spectometry (MS) detection and Emanation Thermal Analysis (ETA).

The sentences: ETA made it possible to characterize the thermal behaviour of the solid samples in their subsurface up to 100 nm from the surface labelled with radon atoms and revealed early microstructure changes of the samples that took place on samples heating. Moreover, ETA results made it possible to characterize differences in the thermal behaviour of zinc oxide resulting from the zinc(II) benzoate complex compounds studied. were deleted.

And new sentences were given:From TG and DTA results it followed that the oxidative degradation of urea with CO2 or caffeine with CO2 from the investigated Zn(II) benzoate complex compounds takes place as the first step of their thermal degradation. In the second step of thermal degradation diphenylketone was release. The Evolved Gas Analysis has been used to determine intermediate products of thermal degradation and temperature ranges of their evolution from the samples.

- row 12

The sentences were changed:

incorrect:From Emanation Thermal Analysisresults of the Zn(II) benzoate compounds it followed that on heating up to 850oC no microstructure changes occurs in the resulting zinc oxide. The break observed on the temperature dependences of radon release rate above 850oC was ascribed to the grain growth or sintering of the zinc oxide samples.

correct:From the Emanation Thermal Analysis results it followed that changes in the surface area and microstructure accompanied the thermal degradation of the compounds studied and that no microstructure changes can be supposed in the resulting zinc oxide on heating from 650 up to 850oC

The dot in Zn(C6H5COO)2.caf2, Zn(C6H5COO)2.u2:

incorrect: Zn(C6H5COO)2.caf2, Zn(C6H5COO)2.u2

correct: Zn(C6H5COO)2∙caf2, Zn(C6H5COO)2∙u2 (in text also)

The key words were split:

incorrect: zinc(II) benzoate complex compounds with caffeine or urea, DTA

correct:zinc(II) benzoate, caffeine, urea, Differential Thermal Analysis

Introduction:

Pag. 2

- row 4: The sentence was changed:

incorrect:Zn2+ ion strongly interacts with electronegative sulphur, nitrogen, oxygen and yet it is not redox active, it does not promote the formation of toxic radicals [2].

correct:Zn2+ ions strongly interacts with electronegative sulphur, nitrogen, oxygen, nevertheless it does not promote the formation of toxic radicals [2].

- row 7 - 12, Sentences in these rows were changed:

incorrect: In recent years we have studied the biological, thermal and spectral properties of some zinc(II) aromatic and aliphatic carboxylates and their halogenoderivatives with N- and O- donor ligands [4-8].

In the present paper work thermal behaviour of novel zinc(II) benzoate complex compounds with caffeine or urea, namely Zn(C6H5COO)2, Zn(C6H5COO)2.caf2, Zn(C6H5COO)2.u2 is described.

correct:In the recent years we have studied the biological, thermal and spectral properties of some zinc(II) aromatic and aliphatic carboxylates with N- and O- donor ligands [4-8]. The thermal degradation of zinc(II) benzoate Zn(C6H5COO)2 was studied by Gusejnov et al. [9].

In this paper the thermal behaviours of zinc(II) benzoate and zinc(II) benzoate complex compounds with caffeine and urea, namely Zn(C6H5COO)2, Zn(C6H5COO)2·caf2, Zn(C6H5COO)2∙u2 are described.

Experimental:

The all part in Samples and their preparationwas changed:

incorrect: Following solid samples ofzinc(II) benzoate complex compounds with caffeine or urea were used in this study. Their chemical composition can be described as follows:

Zn(C6H5COO)2, Zn(C6H5COO)2.caf2, Zn(C6H5COO)2.u2, where abbreviation cafis for caffeine and the abbreviation u is for urea. The samples were prepared as described in [9] and previously characterized by elemental analysis, FTIR spectroscopy and mass spectrometry.

correct:Zinc(II) benzoate and two newly prepared zinc(II) benzoate complex compounds with caffeine and urea, respectively were studied. Following A. R. grade chemicals were used for the samples preparation: ZnCl2 p.a., Na2CO3 p.a. (Lachema Neratovice), benzoic acid 99% (Aldrich), urea and caffeine (Merck). The synthesis of the compounds is expressed by following equations:

ZnCl2 + Na2CO3 → ZnCO3 + 2NaCl(1)

ZnCO3 + 2 C6H5COOH → Zn(C6H5COO)2 + H2CO3(2)

Zn(C6H5COO)2 + 2L → Zn(C6H5COO)2.L2(3)

where L= caf or u

ZnCO3 was prepared by using solutions of the stoichiometric amounts of ZnCl2 and Na2CO3 as described in Eq. (1). The water-alcohol solution of carboxylic acid was added to the water suspension of ZnCO3 under continual stirring in hot water at 70ºC. After one hour, the solution of zinc(II) benzoate was filtered off and the aqueous solution of a ligand (caffeine, urea) was added to the filtrate. The reaction mixture was stirred for 3 hours, then filtered off and left to stand to crystalize at room temperature. After several days white crystals were formed as a precipitate. The precipitates of the formed Zn(II) benzoate complex compounds were filtered off, washed with water and dried over silicagel. The compounds of the following formula were prepared:

Zn(C6H5COO)2(I)Zn(C6H5COO)2.caf2(II)Zn(C6H5COO)2.u2(III)

Where abbreviations caf is for caffeine and u is for urea.

The yields of the reaction were 82% for the compound denoted as (I), 92% for the compound denoted as (II) and 78% for the compound denoted as (III) [10]. Elemental analysis, FTIR spectroscopy and mass spectrometry were used to characterize the samples composition.

Methods used for samples characterization

- row 1: The new sentence was given:Infrared spectra were measured by the Perkin Elmer Spectrophotometer (in the range 4000 – 400 cm-1 using KBr pellets) and by the Bruker Vertex 70 FTIR Spectrophotometer (in the range 1100-200 cm-1 using CsI technique).

row 1: incorrect: DTA

correct: Differential Thermal Analysis (DTA)

incorrect: MS

correct: Mass Spectrometry (MS)

Pag. 3,

row 10Thenew sentence was given:ETA was used to characterize microstructure changes and the thermal behaviour of the samples in their subsurface up to 100 nm labelled with radon atoms.

Results and discussion:

Pag. 3

row 1,incorrect:results of the compound Zn(C6H5COO)2 are...

correct:results of the zinc(II) benzoate compound Zn(C6H5COO)2

- in all text the enumerations:incorrect: at xxxºC and yyyºC

correct: at xxx and yyyºC

- row 2, the sentences:. On heating above this temperature thermal decomposition takes place as indicated by the mass decrease observed on the TG curve in Fig. 1.as indicated by the mass decrease observed on the TG curve in Fig. 1. The release of (C6H5)2CO and CO2 (experimental mass loss value 73.1%, calculated mass loss 73.55%) in the temperature range 280-540°C were observed by TG. This was accompanied by an DTA exothermic effects at 423°C and at 476°C respectively (for DTA curve see Fig. 1).

were changed at:

The release of (C6H5)2CO and CO2 was characterized by the mass decrease in the temperature range 280-540°C as demonstrated on the TG curve in Fig.1. From the DTA curve in Fig 1 it followed that exothermic effects were observed at 423 and 476°C, respectively.

After this sentence anew sentence was given:

The release of (C6H5)2CO was confirmed by IR spectra and by mass spectrometry results. It was found that after heating the sample to 330°C, the absorption band of carboxylate group νas(COO-) at 1638 cm-1 was missing.

- row 8,the sentence was changed:

incorrect: The final solid product of the thermal decomposition is ZnO (experimental mass loss 26.9%, calculated mass loss 26.46%).

correct:The residue mass values of the final degradation product ZnO as well as of the intermediate products of the thermal degradation are presented in Table 1.

- row 10,the sentence was changed:

incorrect: The following mechanism is proposed for the thermal decomposition.

correct:The following mechanism is proposed for the thermal decomposition of compound Zn(C6H5COO)2.

- row 12, The sentence: When comparing the final products of thermal degradation the zinc(II) benzoate with those of barium benzoate it should be mentioned that while ZnO is the final product of degradation of zinc(II) benzoate, BaCO3resulted from the degradation of barium benzoate [14]. was deleted and changed into sentence:Unlike the zinc(II) benzoate for barium benzoate the final product is BaCO3. [15].

Pag. 4

- row 9-11, The sentences were changed:

incorrect: From the ETA curve (Fig. 1) it followed, that no microstructure changes could be supposed in the resulting zinc oxide up to 850oC. The increase and subsequent decrease of radon release rate above 850oC was ascribed to the grain growth or sintering of the sample.

correct:The increase of the radon release E(T) on heating above 650oC was due to the radon diffusion by volume mechanism in the zinc oxide sample. From the exponential character of the ETA curve (Fig. 1) it can be expected that no microstructure changes occurs in the resulting zinc oxide up to 850oC. From the break observed on the ETA curve in Fig. 1 we assumed that on further heating the growth of grains or sintering of the finely powdered zinc oxide sample occurs on heating above 900oC.

In parts Thermal behaviour of Zn(C6H5COO)2∙caf2 and Thermal behaviour of Zn(C6H5COO)2∙u2

The word: molecules were changed into word mole

Thermal behaviour of Zn(C6H5COO)2∙caf2

- row 1, the sentence was changed:

incorrect:From TG results in Fig. 2 it followed that the thermal decomposition of Zn(C6H5COO)2.caf2 compound starts to decompose at 190°C.

correct: From TG results presented in Fig. 2 it followed that the thermal decomposition of Zn(C6H5COO)2·caf2 starts at 190°C.

- row 3,incorrect: by an endothermic effect at 220°C on DTA curve.

correct:by TG results and by an

- row 4, incorrect:The experimentaly found mass loss in this temperature range was 60.57%, the calculated mass loss was 62.12%.

correct: The experimentaly found mass loss in this temperature range are summarized in Table 1.

- row 5,Thenew sentence was given: The release of caffeine was confirmed by IR spectra measurred up to 290°C, where the characteristic bands of caffeine ν(C=O) at 1704 cm-1, ν(C=N) at 1657 cm-1 and ν(C-H)(CH3-)caff at 2949 cm-1 were missing.

- row 6, incorrect: (experimental value of mass loss 28.58%, calculated mass loss 26.18%)

correct: (for the mass loss values see Table 1)

- row 10,incorrect: ZnO resulted as the solid final product of the thermal decomposition of the compound (experimental residue mass 10.85%, calculated residue mass 11.69%)

correct: ZnO resulted as the solid final product of the thermal decomposition and residue mass values are summarised in Table 1.

Pag. 5

row 4,The sentences were changed:

incorrect: ETA results in Fig. 2 made it possible to assume that no microstructure changes of zinc oxide as the solid product of the thermal degradation of the Zn(II) benzoate complex compound can be expected on heating up to 850 oC. Nevertheless, from the break observed on further heating on the ETA curve in Fig. 2 we assumed that a growth of grains or sintering of the finely powdered zinc oxide can be expected on heating above 900 oC .

correct:From the exponential- like character of the temperature dependence of the radon release rate E(T) in Fig. 2 it followed that no microstructure changes occurs on heating from 650oC to 1050oC in zinc oxide formed after the thermal degradation of the Zn(II) benzoate complex compound with caffeine.

Thermal behaviour of Zn(C6H5COO)2∙u2

-row 2, New word was given into the sentence:

incorrect:The compound is stable..

correct:The compound isthermallystable.

The sentence was changed:

incorrect: In the first step in the temperature range 128-340°C two urea molecules and one molecule of CO2 are released (experimental mass loss 37%, calculated mass loss 38.34%).

correct:In the first step in the temperature range 128-340°C two urea molecules and one molecule of CO2 are released, the corresponding experimental and calculated mass loss values are presented in Table 1.

- row 4: anew sentences were given:The release of urea in the first step was confirmed by IR spectra of solid intermediates measurred up to 160°C, where the characteristic absorption bands νas(N-H)u at 3404 cm-1, νs(N-H)u at 3316 cm-1 and ν(C=O) at 1647 cm-1 were missing [10]. In the second step the (C6H5)2CO was released in the temperature range 340-605°C. The (C6H5)2CO decomposed to the ions C6H5CO+ (m/z = 105) and C6H5+ (m/z = 77) [10].

- row 6, (experimental mass loss 44.3%, calculated mass loss 42.60%) was deleted

incorrect:one exothermic

correct:an exothermic effect

Pag. 5 The sentences after mechanism

Zn(C6H5COO)2·u2 2u + CO2 + (C6H5)2CO + ZnO were changed:

incorrect:From the ETA results it followed that the pre-melting processes took place that were expressed by a sharp decrease of radon release from 120oC to 170oC (Fig. 3). The melting of the sample was characterized by an endothermic DTA effect with the maximum at 122oC. The increase of radon release in the range from 130oC up to 350oC reflected a loosening of the structure due to release of the volatile products from the sample during its thermal degradation. The break at 400oC and the following decrease of the radon release rate accompanied the next step of the thermal degradation of the sample as reflected by the volatile products detected by MS and by an DTA exothermal effect. The resulting zinc oxide as the solid residue of the thermal decomposition has a relatively low value of radon release rate. A small effect on ETA curve from 650 – 700oC can be associated with the release of water from the sample (see MS peak with m/z = 18 in the Fig. 3). From the ETA curve it followed, that no considerable morphology changes could be supposed in the zinc oxide up to 850oC. The increase and subsequent decrease of radon release rate above 850oC was be ascribed to the grain growth or sintering of fine grains of the zinc oxide powder.

correct:From the ETA results in Fig. 3 it followed that the pre-melting of the sample, characterized by the break and the subsequent decrease of the radon release rate, took place on heating from the temperature of 120oC. The increase of radon release in the range from 130oC up to 350oC reflected a loosening of the structure due to release of the volatile products from the sample during its thermal degradation. The break at 400oC and the following decrease of the radon release rate accompanied the next step of the thermal degradation of the sample as reflected by the volatile products detected by MS and by the DTA exothermal effect. Zinc oxide as the solid residue after thermal degradation of Zn(C6H5COO)2·u2 is characterized by a relatively low value of radon release rate E(T). The exponential like character of the E(T) dependence on heating above 750oC is due to the radon diffusion by volume mechanism; we assume that no considerable morphology changes took place in the zinc oxide up to 850oC. The break and subsequent decrease of radon release rate E(T) on heating above 900oC makes it possible to expect the growth or sintering of fine grains of the zinc oxide powder prepared by the thermal degradation of the Zn(II) benzoate complex with urea.

Conclusions

All the text in conclusions were changed:

incorrect: From the results of the TG and DTA it is concluded that the release of organic ligands from the Zn(II) benzoate complex comopuds takes place as the first step of the their thermal degradation, the carboxylate anion decomposes as the following step, being accompanied by the release of CO2 and diphenylketone (see Table 1). ETA results revealed early microstructure changes of the samples on heating. Zinc oxide was determined as afinal product of thermal degradation of the compounds at the temperature of 600°C. The Emanation Thermal Analysis made it possible to characterize diffusion properties of the ZnO as the final product of the thermal degradation. From ETA results of the Zn(II) benzoate compounds investigated it followed that on heating up to 850oC no microstructure changes could be supposed in the resulting zinc oxide. A break observed on the temperature dependences of radon release rate on heating above 850oC was ascribed to the grain growth or sintering of the zinc oxide samples. The ETA results characterized differences in the thermal behaviour of zinc oxide resulting after thermal degradation of the zinc(II) benzoate complex compounds.

correct:It was found that the oxidative degradation of urea with CO2 or caffeine with CO2 from the investigated Zn(II) benzoate complex compounds takes place as the first step of their thermal degradation. In the second step of thermal degradation diphenylketone was release.

Intermediate products of thermal degradation of the zinc(II) benzoate complex compound were determined by Evolved Gas Analysis. Microstructure changes that accompanied the degradation of the samples were characterized by Emanation Thermal Analysis on heating. Zinc oxide was determined as the final product of thermal degradation after heating the compounds to 600°C. From the smooth exponential-like increase of the radon release rate observed by ETA on sample heating from 650 up to 850oC it followed that no microstructure changes can be expected with the zinc oxide samples in this temperature range. The break and subsequent decrease of radon release rate observed by ETA on heating above 900oC makes it possible to assume the growth or sintering of fine grains of the zinc oxide powders.

Acknowledgement

The number of project was changed:

incorrect:project No. 1/2474/05

correct: project No. 1/0122/08.

References

New reference No. 9 was fill in the text, so numerical data of references after this reference were changed.

In reference number 9 was made some change:

incorrect:

9L. Findoráková, K. Győryová, J. Kovářová, V. Balek, F. A. Nour El-Dien, L. Halás, J.

Therm. Anal. Cal., in press.

correct:

10L. Findoráková, K. Győryová, J. Kovářová, V. Balek, F. A. Nour El-Dien, L. Halás, J. Therm. Anal. Cal., 95 (2009) 3.

Table 1

incorrect: 73.1, 26.9, 62.12, 37.0, 44.3, 18.7, 38.34

correct: 73.10, 26.90, 62.13, 37.00, 44.30, 18.70, 38.37

In Table 1 ºC were deleted at different values

New columns were given in table 1:

Residue mass
exp. / calc.
26.90 / 26.46
10.85 / 11.69
18.70 / 19.03

incorrect:Captions of Tables and Figures

correct:Captions of Figures

Some changes in Captions of Figures:

incorrect:Fig. 1Results of Thermogravimetry (TG/DTG), DTA, Evolved gas analysis (MS detection) and Emanation thermal analysis (ETA) of the compound Zn(C6H5COO)2 measured on heating in air

correct: Fig. 1 Results of Thermogravimetry (TG/DTG), Differential Thermal Analysis (DTA), Evolved Gas Analysis with MS detection and Emanation Thermal Analysis (ETA) of the compound Zn(C6H5COO)2 measured on heating in air

incorrect: Fig. 2Results of Thermogravimetry (TG/DTG), DTA, Evolved gas analysis (MS detection) and Emanation thermal analysis (ETA) of the Zn(C6H5COO)2.caf2 compound measured on heating in air

correct:Fig. 2 Results of Thermogravimetry (TG/DTG), Differential Thermal Analysis (DTA), Evolved Gas Analysis with MS detection and Emanation Thermal Analysis (ETA) of the Zn(C6H5COO)2·caf2 compound measured on heating in air

incorrect:Fig. 3 Results of Thermogravimetry (TG/DTG), DTA, Evolved gas analysis (MS detection) and Emanation thermal analysis (ETA) of the Zn(C6H5COO)2.u2 compound measured on heating in air

correct: Fig. 3Results of Thermogravimetry (TG/DTG), Differential Thermal Analysis (DTA), Evolved Gas Analysis with MS detection and Emanation Thermal Analysis (ETA) of the Zn(C6H5COO)2·u2 compound measured on heating in air

Some changes were made in figures:

incorrect:H2O, CO2+, NO2+,C+ were deleted from figures 1-3

correct: 18+, 44+, 46+, 12+