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PARAMETERS OF THE COMBUSTION OF DIFFERENTIAL PROPELLANT IN MIXTURE OF OXIDANTS: MOLECULAR OXYGEN-OZONE

PARAMETERS OF THE COMBUSTION OF DIFFERENTIAL PROPELLANT IN MIXTURE OF OXIDANTS: MOLECULAR OXYGEN-OZONE

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52



V. A. Babkin, K. V. Sergeeva, E. S. Titova et al.



AIMS AND BACKGROUNDS

The Molecular oxygen and ozone are one of the best oxidants of differential propellant.

Parameters of the combustion of O3 several more, than parameters of O2. Parameters of the

combustions of mixture these oxidants are not evaluated.

The aim of this work is an estimation of parameters of the combustions of differential

propellant in mixture of oxidants (molecular oxygen-ozone) by means of quantum-chemical

calculation of models of these compounds.



METHODICAL PART

Quantum-chemical calculation of mixture of oxidants of differential propellant (O2-O3)

was executed by classical method CNDO/2 in parametrization of Santri-Pople-Segal [1] with

optimization of the geometries by all parameters by standard gradient method. Parameters of

the combustion of under study mixture valued using known computer technologies [2].



RESULTS AND DISCUSSION

Quantum-chemical calculation of configuration of mixture structure (molecular oxygenozone) was executed (Figures 1-4).



(configuration 1).(E0= -242649 kDg/mol, E= -5497 kDg/mol, D=5.23dB)

Figure 1. Electronic structure of mixture structure O2+O3.



Parameters of the Combustion of Differential Propellant in Mixture ...



(configuration 2). (Е0= -241828 kDg/mol, Е= -4695 kDg/mol, D=1.73 dB).

Figure 2. Electronic structure of mixture structure O2+O3.



(configuration 3).(Е0= -243118 kDg/mol, Е= -5977 kDg/mol, D=0.25 dB)

Figure 3. Electronic structure of mixture structure O2+O3.



53



54



V. A. Babkin, K. V. Sergeeva, E. S. Titova et al.



(configuration 4). (Е0= -243430 kDg/mol, Е= -6289 kDg/mol, D=0.31dB)

Figure 4. Electronic structure of mixture structure O2+O3.



The Сonfiguration 4 possesses most importance general energy E0=243430 kDg/mol.

This configuration is the most energy profitable. Parameters of the combustion were valued

for this configuration. Minimum importance of the charge on atom of the oxygen is -0.01 (Fig

4). Parameters of the combustion are valued by this importance. This importance practically

is a charge of traditional oxidant O2. Ozone practically does not influence upon parameters of

the combustion of differential propellants. Parameters of the combustion of differential

propellants in mixture of oxidants (molecular oxygen-ozone) easy to value using computer

technology[3].

Quantum-chemical calculation of mixture of oxidants (O2-O3) was made for the first time

by classical quantum-chemical semitheoretical method CNDO/2 in parametrization of SantriPoppl-Segal with optimization of the geometries by all parameters by standard gradient

method. Optimized geometric and electronic structure of the combination of these oxidants

was received. Parameters of the combustions of mixture of these oxidants were evaluated.

Parameters of the combustion of differential propellants in this mixture of oxidants practically

do not differ from parameters of the combustion in fluid oxygen.



REFERENCES

[1]

[2]



[3]



Segal D. Semitheoretical methods of the calculation of the electronic structures. M.:

World, 1980, P.327.

Babkin V.A., Fedunov R.G. The Algorithm of technologies of complex searching for

new more efficient fluorine-containing oxidants of rocket propellants. Collected articles

of SF of VolgGASA, V.1, 2003, P.16.

Babkin V.A., Cykanov A.V., Fedunov R.G., Lomakin G.S.. Parameters of the

combustion of rocket propellants in protoned fluorine-containing oxidants. Collected

articles of SF of VolgGASA, V.1, 2003, P.101.



In: Advances in Chemistry Research. Volume 8

Editor: James C. Taylor



ISBN 978-1-61209-089-4

©2011 Nova Science Publishers, Inc.



Chapter 5



COBALOXIMES WITH FUNCTIONALIZED

LIGANDS



Alexei A. Gridnev, Dmitry B. Gorbunov

and Gregory A. Nikiforov

N.M.Emanuel Institute of Biochemical Physics,

Russian Academy of Sciences,

Kosygin st., 4, Moscow 119334, Russian Federation



ABSTRACT

Cobaloximes, alkylcobaloximes and borofluoride adducts on the basis of asymmetric

functionalized ligandes have been synthesized. These cobaloxime systems form

geometric isomers. The presence of chiral center in axial ligand gives rise to the

appearance of diastereotopics effect.



Keywords: cobaloximes, alkylcobaloximes, borofluorination, geometric isomers, effect

of diastereotopics.



Cobaloximes are the most active catalysts of chain transfer to monomers in radical

polymerization [1]. Catalytic chain transfer to monomers is the commercially important

process for making of a variety of oligomeric product [2]. For industrial tasks the most

available cobaloxime systems making on the basis of dimethyl- and diphenylglioximes. The

same matters are the basis of the majority of synthetic and physicochemical investigations of

cobaloximes. Only several articles are devoted to cobaloximes with bivalent atom of Co

where

diethyl[3],

methylpropyl[3],

substituted

diphenylglioxime

[4],

CH3C(=NOH)C(=NOH)CO CH3 [5] and C12H25SC(=NOH)C(=NOH)S C12H25 [6] have been

used as equatorial ligands. As to cobaloxime systems in addition to Py[CoDmg2]R and



Alexei A. Gridnev, Dmitry B. Gorbunov and Gregory A. Nikiforov



56



Py[CoDPhg2]R [7-13], the complexes of Py[CoL2]R on the basis of 1,2-dioximino-1-(3,,5,-ditret-butyl –4,-hydroxyphenyl)propane [2] and 1,6-disubstituted of 3,4-dioximinohexane [14]

have been described.

Apparently this situation of the investigations of cobaloximes is connected with the

difficulties of α-diketones synthesis. We synthesized the simplest cobaloxime systems

Py[CoL2]Cl according to Tchugaev, technique [3] by the interaction of α-dioximes

RC(=NOH)C(=NOH)R (R = R, = H or CH3; R = H, R, = CH3; R = CH3, R, = COOEt or

COOC12H25) with Co chloride and NaOH in methanol in the presence of pyridine at intensive

stirring and air stream. The yields and the data of NMR-spectra of the obtained cobaloximes

are given in Table 1.

The analysis of NMR-spectra of Py[CoL2]Cl shows that in the case of symmetric

cobaloximes (R=R, = H or CH3) the signals from H and CH3 are singlets but for asymmetric

cobaloximes (R= CH3, R, = H, COOEt or COOC12H25) H and CH3 give two singlet signals

with the approximately equal intensity, the difference of the chemical shifts of these groups is

0.02–0.05 ppm. Moreover, in the case of cobaloxime Py{Co[CH3C(=NO)C(=NOH)

COOC12H25]2}Cl the signals from protons of pyridine and first metylene unit of ester

fragment are also doubled. These facts testifies that during the reaction asymmetric αdioximes gives with equal probability two geometric isomers of cobaloxime:

H

O



O

R



H



Cl

N



N



R1



R1



Cl

N



Co

R1



N



N

Py



O



O

H



O



O



N



R1



Co

R



R



N



N

Py



O



R



O

H



The existence of such isomers is confirmed also by the data of chromatographic analysis.

These isomers are developed clearly as two spots on the plate DC-Plastikfolien Kieselgel 60

F254 in eluent system chloroform – acetone (1:1). In addition more mobile isomer of

cobaloxime Py{Co[CH3C(=NO-)C(=NOH)COOC12H25]2}Cl we can separate by column

chromatography (SiO2, 40/60μ, eluent – chloroform) as rather clear product. Data of it NMR

spectrum are given in Table 1.



Table 1. Cobaloximes Py{Co[RC(=NO-)C(NOH)R’]2}Cl

R



R’



H



CH3



CH2CH3



NMR-spectrum, δ, ppm.

CH12H25

HPy



Solute

DMSO



Yield %



H



H



74



7.89



-



-



-



CH3



H



68*



-



CH3



90



2,.26

2.27

2.28



-



CH3



7.81,

7.91

-



-



-



CH3



COOC2H5



85*



-



COOC12H25



80*



-



1.34(dt)

4.38(q)

-



-



CH3



2.50

2.52

2.46

2.51**



0.87(t),1.25(m),

1.71(m),4.10(t),

4.31(t)**



7.51(t),7.93(t),

8.00(d)

7.50(dt),7.91(dt),

8.21(dd)

7.50(t),7.90(t),

8.18(d)

7.61(t),8.07(t)

8.18(d)

7.20(t),7.65(t),

8.52(d),7.30(t)**,

7.78(t)**,8.18(d)**



DMSO

DMSO

acetone

CDCl3



*) The mixture of geometric isomers (the ratio ≈ 1:1).

**) The signals of more mobile isomer.



Table 2. Аlkylcobaloximes Py{Co[RC(=NO-)C(=NOH)R]2 }CH(CH3)X

R



X



Yield %



H



COOCH3



23



CH3



CH3



90



H (e)

7.47(s)

7.50(s)

-



CH3



CH2CH3



84



-



CH3



Ph



75



-



CH3



COOCH3



81



-



CH3



CN



86



-



CH3



CONH2



62



-



NMR-spectrum (CDCl3, δ, ppm)

CH (a)

X

2.22(q)

3.54(s)



CH3(e)

-



CH3(a)

0.38(d)



2.12(s)



0.47(d)



1.93(q)



0.47(d)



2.06(s)

2.11(s)

1.93(s)

1.96(s)

2.18(s)

2.20(s)

2.23(s)

2.26(s)

2.19(s)

2.21(s)



0.42(d)



1.70(q)



1.64(m) 0.79(t)



0.62(d)



3.57(q)



7.22(m)



0.38(d)



2.14(q)



3.47(s)



0.56(d)



2.19(q)



-



0.41(d)



2.09(q)



4.89(s)

5.42(s)



HPy

7.34(t),7.75(t)

8.50(d)

7.28(t),7.67(t)

8.58(d)

7.26(t),7.66(t)

8.56(d)

7.24(t),7.66(t)

8.49(d)

7.26(t),7.69(t),

8.48(d)

7.31(t), 7.74(t),

8.47(d)

7.28(t),7.68(t),

8.48(d)



58



Alexei A. Gridnev, Dmitry B. Gorbunov and Gregory A. Nikiforov



For discovering of structure peculiarities of cobaloxime systems where the possibility of

geometric isomerism is excluded symmetrical alkylcobaloximes on the basis of glyoxime and

dimethylglyoxime were obtained Py{Co[R-C(=NO-)C(=NOH)R]2}CH(CH3)X (2) according

this scheme:

R-C(=NOH)C(=NOH)R + CoCl2 + 2NaOH + Py →

Py{Co[R-C(=NO-)C(=NOH)R]2}

(1) + H2 → Py{Co[R-C(=NO-)C(=NOH)R]2}H + CH2=CHX →

R = CH3, X = Ph, COOCH3, CN, CONH2

(1) + NaBH4 → Py{Co[R-C(=NO-)C(=NOH)-R]2}H + CH3СHBrX →

R = H, X = COOCH3; R = CH3, X = CH3, CH2CH3



(1)

(2)

(2)



Alkylcobaloximes (2), as a rule, during the reaction are crystallized well from methanol

medium and are rather clean samples after washing by water and methanol. The yields and

data of NMR spectra of alkylcobaloximes are given in Table 2. The analysis of NMR spectra

of symmetrical alkylcobaloximes (2) shows that in the case of R=CH3, X = CH3 singlet signal

of protons of equatorial ligands is observed but for the other (R = H, X = COOCH3; R = CH3,

X = CH2CH3, Ph, COOCH3, CN, CONH2) doublet is observed. Analogous data are given in

[10]. The difference of investigated alkylcobaloximes (2) consists in the presence of

asymmetrical carbon atom in axial ligand at X = CH2CH3, Ph, COOCH3, CN, CONH2. Then

in equatorial ligands the substitutes H and CH3 are in couples diastereotopic and have to

develop at NMR spectra as two singlets of the equal intensity. The difference of the chemical

shifts of these groups, as a rule, is 0.01- 0.03 ppm as it takes place in [8]. The effect of

diastereotopics is not developed in the case of axial ligands protons. For creating of more

complicated alkylcobaloxime systems with geometric isomerism and the effect of

diastereotopics asymmetric α-dioximes CH3C(=NOH)C(=NOH)COX (X=OCH2CH3,

OC12H25, NHPh, NH-C6H4COOC2H5) were used. We choose СH(CH3)COOCH3 fragment as

axial alkyl ligand.

Starting compound at the synthesis of dioximes was tert.butyl ester of acetoacetic acid. It

contains the fragment of activated methylene unit and this fact allows easily transforming it

into α-dioxime and ester-group and then into different functional derivatives (esters, carbonic

acids, nitrils, amides and so on). This ester is labile and easily undergoes transesterifying by

the high alcohols even in the absence of catalyst. The process of transesterifying proceeds at

95-1100C with separating of tert.butyl alcohol from reaction medium. The use of dodecyl

alcohol for transesterifying gave rise to corresponding ester with 93-94% yield (Table 3). It

can be expected that the interaction of tert.butyl ester of acetoacetic acid with amines also will

proceed rather easily with the formation of corresponding amides. In fact the heating of the

ester with aniline or the ester of p-amino benzoic acid at 120-1400C with simultaneous

moving off of tert. butyl alcohol in Ar stream gave rise to corresponding amides with 70-85%

yield (Table 3). The amidating occurs irreversibly. As a rule, the end amide forms crystal

phase, which may be easily separated from the excess of the ester and resin products.

The nitrozation of the obtained esters and the amides of acetoacetic acid by NaNO2 at 00

5 C in CH3COOH gives the derivatives of 2 oximino-3-ketobutiric acid (Table 3).



Cobaloximes with Functionalized Ligands



59



Table 3. The derivatives of acetoacetic acid

X



CH3COCH2COX



CH3COC

(=NOH)COX



CH3C(=NOH)

C(=NOH)COX



Yield %



M.p.,0C



Yield %



M.p 0C



Yield %



M.p., 0C



OCH2CH3



-



-



52



56-57



80



154-155



OCH2(CH2)10CH3



96



оil*



97



oil*



61



90-91



NHPh



71



85-86



83



97-98



77



224-225



NHPh-4COOCH2CH3



86



123-124



80



163-164



96



209-210



*) Degradation at the distillation.



Corresponding α-dioximes have been obtained by the standard technique of oximating by

hydrochloric hydroxylamine in methanol at the presence of equivalent of NaOAc at the room

temperature (Table 3):

CH3COCH2COOt.Bu → CH3COCH2COX → CH3COC(=NOH)COX →

i

ii

iii

CH3C(=NOH)C(=NOH)COX

(i) 110 – 1400C, Ar, distillation of t.BuOH

(ii) NaNO2, 0 – 50C, AcOH, 2 h

(iii) NH2OH.HCl, 200C, EtOH, 3-5 h

The structure of the esters and amides of acetoacetic acid, monooximes and dioximes is

confirmed by the data of element analysis and NMR-spectra.

The synthesis of alkylcobaloximes on the basis of the mentioned dioximes was carried

out with the use of the standard natrium borohydride technique [5]:

2CH3C(=NOH)C(=NOH)COX + CoCl2 + NaOH + Py →

Py{Co[CH3C(=NO-)C(=NOH)COX]2} + NaBH4 →

Py{Co[CH3C(=NO-)C(=NOH)COX]2}H + CH3СHBrCOOCH3 →

Py{Co[CH3C(=NO-)C(=NOH)COX]2}CH(CH3)COOCH3

As

a

result

the

mixture

of

geometric

isomers

of

cobaloximes

Py{Co[CH3C(=NO)C(=NOH)COX]2}CH(CH3)COOCH3 is formed. This mixture may be

easily separated from resin products by chromatographic technique (SiO2) as orange-brown

resins which become hard as amorphous mass at grinding with hexane. The crystal form as

orange-brown plate crystals is formed at the transprecipitation of the isomers mixture by

water from methanol. According to the data of NMR-spectrum (Table 4) it is of two isomeric

alkylcobaloximes in the ratio 1 : 1. The mobility of these isomers in the system chloroform –



60



Alexei A. Gridnev, Dmitry B. Gorbunov and Gregory A. Nikiforov



acetone (1:1) at the plate DC-Plastikfolien Rieselgel 60 F254 has a little difference. But we can

not separate the isomers even at these plates. Only in the case of Х = ОС12Н25 and R =

CH(CH3)COOCH3 substantial increase of keeping of more mobile isomer in the mixture is

observed. The yields and the data of NMR-spectra are given in Table 4.

As the geometric isomerism as the effect of diastereotopics must be shown in NMRspectra of asymmetric alkylcobaloximes. Then, doubling of the signals of protons of axial

ligand C(CH3)COOCH3 is caused by geometric isomerism only; but doubling of the signals

of protons of equatorial ligands of these cobaloximes connects as diastereotopics as a

presence of geometric isomerism.

Unexpected results have been obtained by us at the synthesis and spectral investigations

of borofluoride adducts of akkylcobaloximes. For this synthesis we used the known technique

of Schrauzer [7] developed for B[CoDmg2]CH3 (B = Py, H2O). As starting agents we used

alkylcobaloximes Py[CoDmg2]R (R = CH(CH3)2, CH(CH3)CN and CH(CH3)COOCH3).

According to the stoichiometry the process of the diadduct synthesis is described by this

scheme:

Py[CoL2]R + 2Py + 4BF3.Et2O → Py[Co(LBF2)2]R + 2PyHBF4 + 4 Et2O.

Then, ideal molar ratio of starting products for obtaining of diadduct must be Py[CoL2]R

/Py /BF3.Et2O = 1: 2: 4. Approximately the same ratio Schrauzer used at the synthesis of

Py[Co(DmgBF2)2]CH3 [5]. The reaction was carried out in dry ether at 200C with stirring of

the suspension during 48 h.

The transfer of these conditions into Py[CoDmg2]CH(CH3)2 instead of expected diadduct

gave rise to the complicated mixture, containing the substantial quantity of starting

cobaloxime and borofluoride adducts one of which we can separate. According to the data of

element analysis and NMR-spectra it is monoadduct Py[Co(Dmg)(DmgBF2)]F.

Alkylcobaloximes are weakly soluble in ether. This fact is the reason of increasing of the

process time. Then we use at further experiments THF as a solvent. It allowed to carry out the

reaction in homogenous conditions, considerably decrease its time and to obtain the reaction

mixtures which composition is determined by the reaction time. At the same time, as a rule,

the mixtures of some substances are formed. Then the task was to separate them. The

treatment of the residue after THF moving off by water allowed putting away PyBF4.

Cobaloxime Py[Co(Dmg)(DmgBF2)]F was separated due to its pour solubility in chloroform

and acetone. At the first time we can separate starting cobaloxime and its borofluoride

adducts with the chromatographic method at neutral SiO2 (40-60 μ), eluent – the mixture of

acetone and chloroform = 9 : 1 (vol).



Table 4. Аlkylcobaloximes Py{Co[CH3C(=NO-)C(=NOH)COX]2}CH*(CH3*)COOCH3*

CH3

2.31(s)

2.32(s)



X

1.35(t)

4.35(q)



CH*

2.42(q)

2.46(q)



CH3*

0.46(d)

0.52(d)



COOCH3*

3.51(s)

3.53(s)



49



2.31(s)

2.32(s)



2.49(q)

2.50(q)



0.46(d)

0.51(d)



.51(s)

3.52(s)



48



2.60(s)

2.61(s)



0.88(t)

1.26- 1.71(m)

4.27(t)

7.37(m)

11.72(d)



2.71(m)



0.51(d)

0.58(d)



3.49(s)

3.54(s)



59



2.61(s)

2.62(s)



1.31(t),1.37(t)

4.21(q),4.35(q)

7.07(d) 8.03(d)

10.69(d)



2.70(m)



0.52(d)

0.56(d)



3.48(s)

3.50(s)



56

OCH2CH3



OCH2-(CH2)10-CH3



NHPh



NHPh-4COOCH2CH3



HPy

7.35(t)

7.77(t)

8.42(d)

7.33(t)

7.75(t)

8.43(d)

7.60(t)

8.01(t)

8.69(d)

7.60(t)

8.04(t)

8.55(d)



62



Alexei A. Gridnev, Dmitry B. Gorbunov and Gregory A. Nikiforov



The composition of these mixtures depends on the reaction time and the quality of

pyridine added to reaction mixture. Starting cobaloxime practically completely disappears at

the reagent ratio Py[CoDmg2]CH(CH3)2/BF3.OEt2/Py = 1 : 4 : 2 and 3-4 h standing, the yield

of Py[Co(Dmg)(DmgBF2)]F increases with the reaction time. The yield of monoadduct

Py[Co(Dmg)(DmgBF2)]CH(CH3)2 achieves the maximum in 3 –4 h and then decreases but

the yield of Py[Co(Dmg)(DmgBF2)]F increases. It testifies that during the reaction the axial

alkyl fragment changes into fluoride evidently by the action of Py-salt of HBF4 presented in

the reaction mixture:

Py[Co(Dmg)(DmgBF2)]CH(CH3)2 + PyHBF4 → Py[Co(Dmg)(DmgBF2)]F.

We can suppose that the borofluoriding process occurs in several steps and the process of

Py[Co(Dmg)(DmgBF2)]F formation competes with the formation of diadduct

Py[Co(DmgBF2)2]CH(CH3)2. The decrease of Py quantity in the system gives rise to as delay

of Py[Co(Dmg)(DmgBF2)]F formation as an appearance in the reaction mixture of

monoadduct H2O[Co(Dmg)(DmgBF2)]CH(CH3)2 and diadduct H2O[Co(DmgBF2)2]

CH(CH3)2. This fact is very interesting as it testified that the introduction of pyridine into

reaction system gives rise to only the undesirable competition of two mentioned processes.

Apparently the reason is such that initially at the addition of Py the change of ether ligand of

BF3.Et2O to pyridine with the formation of less reactive BF3.Py is occurred.

Then borofluoriding of Py[CoDmg2]CH(CH3)2 in THF at the reagent ratio 1 : 4 during 2h

allows to obtain diadduct H2O[Co(DmgBF2)2]CH(CH3)2 with 75% yield. In a similar manner

mono- and diborofluoride adducts of cobaloximes B[CoDmg2]CH(CH3)X (B = Py, H2O, а X

= CN, COOCH3) have been obtained. The of NMR-spectra of borofluoride adducts are given

in Table 5.

As we expected the violation of the symmetry of cobaloxime molecule at the introduction

of one borofluoride group gives rise to XOR in couples of equatorial methyl groups. Two

equivalent singlets are observed in spectra of Py[Co(Dmg)(DmgBF2)]F and

B[Co(Dmg)(DmgBF2)]CH(CH3)2 (B = Py, H2O). At the presence of asymmetric atom C in

axial ligand [R=CH(CH3)CN, CH(CH3)COOCH3] the effect of diastereotopics also takes

place and is a reason of appearance of 4 singlets of equatorial methyl groups in the spectrum

of these cobaloximes.

The introduction of second borofluoride group to cobaloxime molecule restores the

symmetry of the system, equatorial methyl groups become equivalent and one or two singlets

(at the presence of diastereotopics) are observed in spectrum.



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