novel high nitrogen insensitive energetic materials · “synthesis of advanced energetic...

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Presented at Workshop on

“Synthesis of Advanced Energetic Materials-

The Path Forward”

Inn and Conference Center on the

University of Maryland College Park campus

April 3-5, 2011

By

Farhad Forohar and Grissell Carrero-Martinez

Naval Surface Warfare Center, Indian Head, MD 20640-5102

Email: [email protected]

Novel High Nitrogen Insensitive

Energetic Materials


Objective

The main objective is to develop energetic materials

with high thermal stability and insensitivity to impact,

friction, and electrostatic discharge.


Background

Looking into the chemical literature indicates that there is

inherent thermal stability in some ring systems such as

dibenzotetraazapentalene (TACOT) and

dipicrylbenzobistriazoledione.

N

N

N

N

N

N

O

O

NO 2O 2N

O 2NNO 2

O 2NNO 2

Dipicrylbenzobistriazoledione

mp = 430 °C

d = 1.80g/cc


Compounds of Interest

N

N

NRTT B

N

NN

R

N

N

N

R

Triazole units fused into

one ring system. Such a

ring system has the

advantage of being rich

in nitrogen content, as

well as having high

thermal tolerance. Where R is: Nitroimidazole, H, NO2, Nitroalkyl, etc.


Holden calculation for some of the proposed molecules are listed below:

R Density(g/cc)

NO2 2.00

Trinitroimidazole 2.00

Dinitroimidazole 1.98

F 1.98

H 1.76

Holden Calculations

N

N

NR

N

NN

R

N

N

N

R


A 1952 article in a Czech. publication describes synthesis of tris(alkyltriazolo)benzene ring system.

(Muzik, F., et al., Org. Res Inst., Czech, 1952, 46, 774).

A1993 Russian publication, by Samsonov et al., reports the synthesis of unsubstitutedtris(triazolo)benzene.

(Khimiya Geterotsiklicheskikh Soedinenii, No. 10., pp. 1364-1367, October, 1993).

Literature Search


Synthesis of Tris(triazolo)benzeneNH 2

H 2N NH 2

+

NH 2

H 2N NH 2

N=NN=N

N=N

C 6H 4(NO 2)

C 6H 4(NO 2)

(O 2N)C 6H 4

C uSO 4

N

N

N(O 2N)C 6H 4

N

NN

C 6H 4(NO 2)

N

N

N

C 6H 4(NO 2)

N

N

N

N

NN

N

N

N

O 2N

NO 2

NO 2

O 2N

NO 2

H N O 3

H 2SO 4

1) C H 3O N a in C H 3O H

2) H C l

HN

N

N

NH

NN

HN

N

N

H 2O .

M elting Point > 360 °C

M elting Point 300 °C

(Sam sonov et al., K him iya G eterotsiklicheskikh Soedinenii,

N o. 10., pp. 1364-1367, O ctober, 1993)

Pyridine

NH 2

NO 2

H C l, N aN O 2


Synthesis of Tris(nitrotriazolo)benzene,

(TNTB)

TNTB

H 2O .

(C H 3C O )2O + H N O 3

-5 oC

N

N

N

N

NN

N

N

N

N O 2

O 2N

NO 2

N

N

N

N

NN

N

N

N

H

H

H


13C NMR of TNTB

N

N

N

N

NN

N

N

N

NO 2

O 2N

NO 2

(in acetone, d6)


IR of the Powder Form of TNTB


TNTB Crystallization

TNTB crystallized out of acetone/water mixture.

N

N

N

N

N N

N

N

N

NO 2

O 2N

NO 2

N

N

N

N

N N

N

N

N

NO 2

NO 2

O 2NOr


Picture of the Crystals


X-ray Crystallography

By Dr. Damon Parrish at NRL

It shows the crystals are

bis(2N-nitrotriazolo)triazolobenzene .

Note the two water molecules.


IR of Yellow Crystals

93.0

93.5

94.0

94.5

95.0

95.5

96.0

96.5

97.0

97.5

98.0

98.5

99.0

99.5

100.0

%T

500 1000 1500 2000 2500 3000 3500 4000

Wavenumbers (cm-1)


What Happened?

During crystallization decomposition takes place.

When the powder or the crystal is kept in a closed

vial, after a few days at room temperature a strong

acidic smell develops.

The crystals are stable in the freezer.

Crystallization in the absence of water may form

more stable crystals.


N-Chlorination of TTB

An Intermediate for Further Reactions

N

N

N

N

NN

N

N

N

Cl

C l

C l

N

N

N

N

NN

N

N

N

H

H

H

B leach (N aO Cl)

CH 3C O O H

TCTB

TCTB was found to be a very interesting molecule.

TTB


Mass Spectrum

N

N

N

N

NN

N

N

N

C l

C l

C l

H

C 6H C l3N 9

m /e: 303.94205 (100.0% )

305.93910 (95.9% )

307.93615 (30.6% )


Heat of formation (calculated by Joe Hooper at NSWCIHD to

be 3900 kJ/kg) is 3.8 times higher than that of CL-20.

Holden calculation predicts a density of 1.94 g/cc.

Stable under ambient conditions. Rapidly decomposes at

211 ºC.

Preliminary tests show it is not impact or friction sensitive.

It is a new oxidizer.

It is hypergolic with PRIMARY LIQUID amines such as:

aniline, hydrazine, diethylenetriamine and

hydroxyethylethylenediamine.

Some Properties of TCTB


Hypergolic with Hydrazine


Hypergolic with Hydrazine Cont’d


Potential Applications

An initiator. IRFNA (Inhibited Red Fuming Nitric Acid) is used

in rocket propulsion. IRFNA is “extremely corrosive”.

An oxidizing agent.

A chlorinating agent.

N-chloramines are used for wastewater treatment, disinfectant

in military kitchen services, and in dishwashing compositions.

By analogy it should be a stronger reagent than the

commercially available N-chlorotriazolobenzene.


1-Chlorobenzotriazole Has

Commercial Uses


1-Chlorobenzotriazole

Has Many Applications

M. P. Braun and C. R. Johnson, 1-Chlorobenzotriazole, in The Encyclopedia of Reagents, L.

Paquette, Ed., John Wiley & Sons Limited, 1995.


Compounds of Interest

N

N

N

N

NN

N

N

N

NO 2

O 2N

Cl

N

N

N

N

NN

N

N

N

C(NO 2)3

(O 2N)3C

C(NO 2)3


•Novel nitro tristriazolobenzenes were made.

One structure was confirmed by X-ray crystallography.

•Tris(chlorotriazolo)benzene was made.

It has hypergolic properties.

•Tris(chlorotriazolo)benzene has potential commercial applications as an oxidant, a disinfectant and an energetic hypergolic agent!

Conclusions


Acknowledgments

The ILIR program for the funding.

Alfred Stern

Damon Parrish

MIDN 1/C James Alan Friedlander

Dorothy Cichra

Jesse Moran

Victor Bellitto

Stanley Caulder

Joseph A. Mackey


IR Comparison

84

86

88

90

92

94

96

98

100

102

104

106

108

110

112

%T

500 1000 1500 2000 2500 3000 3500 4000

Wavenumbers (cm-1)

Crystals

Powder

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