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3. DATES COVERED (From - To)
1. REPORT DATE (DD-MM-YYYY)
2. REPORT TYPE
03-24-2004
Technical Paper (View Graph)
4. TITLE AND SUBTITLE
5a. CONTRACT NUMBER
Polynitrogen Chemistry: Recent Development in Pentazole and Polyazide Cliemistry
5b. GRANT NUMBER
F04611-99-C-0025 5c. PROGRAM ELEMENT NUMBER 5d. PROJECT NUMBER
6. AUTHOR{S)
DARP
Ashwani Vij, Vandan Vij, R. Haiges, Karl 0. Christe
5e. TASK NUMBER
A205 5f. WORK UNIT NUMBER 8. PERFORMING ORGANIZATION REPORT NUMBER
7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)
ERC Incorporated 555 Sparkman Drive Huntsville, AL 35816-0000 10. SPONSOR/MONITOR'S ACRONYM(S)
9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES)
Air Force Research Laboratory (AFMC) AFRLyPRSB 4 Draco Drive Edwards AFB CA 93524-7160
11. SPONSOR/MONITOR'S
NUMBER(S) AFRL-PR-ED-VG-2004
12. DISTRIBUTION / AVAILABILITY STATEMENT
Approved for public release; distribution unlimited.
13. SUPPLEMENTARY NOTES
American Chemical Society Meeting (ACS) National Meeting Anaheim. CA 28 Mar - 01 Apr 2004 14. ABSTRACT
20040503 192 15. SUBJECT TERMS
17. LIMITATION OF ABSTRACT
16. SECURITY CLASSIFICATION OF:
a. REPORT Unclassified
b. ABSTRACT Unclassified
18. NUMBER OF PAGES
C. THIS PAGE Unclassified
38
19a. NAME OF RESPONSIBLE PERSON
Linda Talon 19b. TELEPHONE NUMBER (include area code)
(661)275-5865 Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std. 239.18
PolynitrogeB Cheitdstry: Recent Development in Fentazole and Polyazide
Ashwani Vij Space and Missile Propulsion Division Air Force Research Laboratory/PRSP Edwards AFB, CA 93524
[email protected] (661) 275-6278
Inorganic Division,- 227th National ACS Meeting, Anaheim-CA, April 1,2004 Approved for public release, distribution unlimited
%^^
Why Polynitrogen Compounds ?
M-j
■>«2*-
Polynitrogen compounds contain only nitrogen atoms and are expected to have unusual properties. Most important among these are: •
High endothermicity
•
"Green" propellant "combustion" product is only gaseous N^
•
H/fifh density
•
Higli Isp values when compared to other monopropropeliants or bipropellants High detonation velocity
Aprin,20M
Inorganic Division - Main Group Ctiemistiy, 227" National ACS Meeting. Anaheim-OA, April 1, 2004 Approved for public release, distribution unlimited
.N
Calculated Structure
N
Resonance Structure
1.302 A
Experimental Structure
'¥«
L
• Vij, Wilson, Vij, Tham, Sheehy & Christe, J. Am. Chem Soc, 2001,123, 6308-6313
N2 makes contacts at 2.723 and 2.768 A N4 contacts are at 2.887 and 2.814 A C&ENews, 2000, 78. 41
April I, 2004
4
Inorganic Division - Main Group Chemistiy, 22?" National ACS Meeting, Anaheim-OA. April 1, 2004 Approved for public release, dislribullon unlimited
(In)Compatability of N^
"^W :-^'.-.-^v;AS^a^=:5;.JSg:^J:'-a-v-J.':^.~T/=^
Attempts to couple N5+ with energetic anions can result in explosive reactions !!! Ns^Na-
N5^CI04-
b N,+NO,-
N5^N(N02),
Our goal is the synthesis of an "aromatic" poiynitrogen anion with • • April 1, 2004
A high first ionization potential A high activation energy barrier towards decomposition Inorganic Division - Main Qroup Onmislry, 227" National ACS Meeting, Anaheim-CA, April 1, 2004 Approved for public release, distribution unlimited
%J
New Polynftrogen Anions as Counterparts forN.
■tp^
*:i\^'>i
Pentazole anion (Ng-) ' Theoretical calculations show that this anion has a 28 kcal/mole activation energy barrier for decomposition and its decomposition to N^ and N^is only 11 kcal/mol exothermic Free pentazole has not been isolated to date. Only aryl substituted pentazoles can be isolated and stabilized at low temperatures. These compounds rapidly decompose above 273Kto form aryl azides andN^^as April 1,2004
inorganic Division - Main Group Chemistry, 227-" Nalionar ACS Meeting. Anaheim-CA, April 1, 2004 Approved (or public release, dislribulion unlimited
|CJ Synthetic Challenge - How do we make These New Anions??
x^^J^.^
Synthesis of Substituted Pentazoles Sources for the Pentazole Anion (N5-)
Siiyi Diazonium Salts
Aryl Diazonium Salts
^
R—Si-N,^ R^
^i
+N3-
R-K ( R = electron releasing group
))—No+
+N,
R—SiR Unknown April 1, 2004
Inorganic Division - Main Group Chemisliy. 227« National ACS Metling, Anat^BQVyrkpril 1, siro __™ Approved for public relgase, distribution unlimited
I Ugi,Angew Chen.. 1961, 73,172
Formation and Stability of Silyl Diazonium Salts •
Failed attempts to synthesize silyl diazonium salts
N2F+SbF6- + MesSiSiMeg
-MejSiF >^
MesSiNa+SbFg"
R3SiN2+ salts are unstable and spontaneously lose No
RsSiNj^ X-
-N,
RjSi-^ X-
Theoretical calculations support this experimental observation ^
I"°f93* Division - Main Qroup Ohenilstry. 227" Nalional ACS Meeting. Anahelm-CA, April!, 2004 Approved for public release, distribution unlimited
'■ ^°°^
Aqueous Media ^r^\
J^aNO^/HCl
>p^
NaBF4
/P=^ !2*BF4-
This peak is also observed upon adding a base to the solution of arylpentazoles at -30 °C. Inorganic Division - Main Group Chemistry, 227* National ACS Meeting. Anaheim-CA, April 1, 2004 Approved for public release, distribution unlimited
> ESIMS of/j^ra'hydroxyphenylpentazole Vij, Pavlovich, Wilson, Vij, Christe, Angew. Chem. Intl. Ed. Engl 2002, 41,3051 Suhmittcd: April 30,2002; acceptdjuly 3,2002
> '^N NMR studies showing a peak at -10.2 ppm (-40 °C) due to the Pentazole anion resulting from cleavage of/)i?r.a'methoxyphenylpentazoIe which slowly decomposes to form N2 and azide ion. Upon standing for several days, all peaks dissappear! Butler, Stephens & Burke, Chem. Commun. 2003,1016 Suhmittcd: February 6,2003; acctptdFthmary 27,2003
> Laser Desorption lonization (LDI) time-of-flight (TOF) mass spectrometry of solid/i^7ra'iY7V-' ^'^ National ACS Meetino. Anaheim-CA. Apm 1. 2004 Approved for public release, distribulion unlimited
%.ji Reactivity of hexachloroantimonate (Vi) f^ ^^ with Trimethylsilylazide ^}/
[Ph4M][SbCl6]
+
Me3SiN3'^'
[Ph4M][SbCl6.,(N3),:
•3"-
60 °C
M = P, As; x = 2-6
l§iillllilplli|ij|||i||M
liSiliiiiliililiBliiii^ ;il®5i|e|orip^^
■6i
■ sr^,f(5ta|;:5ubst^ "refi-eshment" cycles oftfiereagents: BuiSig the'^ intermediate cycles, the azide content gradually increased from two to five. Apnl 1 2004 1—
'""°°"" °'""°" " "''" °"'"'' '=''™i=">' ^^J'" Naliorial ACS Meelina, Anaheim-CA, April 1, 2004 ——, Approved for public release, distribution unlimited
J
•*2»
The tetraphenylarsonium antimonychloride azide case
,!i.b,c{ ) .7.7744(14), 13.610(3),27.094(5)
, chloride contamination (%) N1-N3 . 10; N4-N6 - 18; N7'N9 ■ 16; N10-N12 - 37
. V . 2866.8(10), Z » 4 R - 3.22%, S - 1088, highest peak • 0.58 e/' >
R ■ 3 22%, S - 1.088, highest peak - 0.58 e/'
HacTt's parameter - 0.03(1)
FlacVs parameter - 0.03(1)
April 1. 2004
1^
Inorganic Division - Main Group Chejtiisliy, 227» National ACS MeeHns. Analieim.CA, April 1,2004 Approved for public release, distribution unlimited
Summary '■^'''"•■"""-
•
Synthesized aryl pentazoles: hydroxy group at the paraposition on the aryl ring gives the best results as observed during this study.
•
Demonstrated selective cleavage of C-N bond by ESIMS with retention of pentazole ring. Results confirmed studying ^^N labeled pentazoles.
•
Experimental detection of pentazolate anion in solution using different substrates.
•
Offers potential pathway for bulk synthesis of Ng- salts
•
Chloride ion cause abnormalities in N-N bonds in azides
April 1, 200d
Iforganic Division - Main Group Chetiiistry, 227"' National ACS Meeting, Anaheim-CA, April 1. 2004 Approved for public release, dislribution unlimited
Acknowledgments
**".»•?■/.
V,
■. Karl Christe, Dr. William Wilson, Ms. Vandana j (ERC Inc.) . Gregory Drake (AFRL) .RalfHaiges(USC) Dr. Fook Tham (UC Riverside)
\i\t Dr.JamesPavlovich(UCSB)
r-.
*"'." ' — - t."' -i-W't -'': ^^- Robert Corley, Dr. Ronald Channell, Mr. j. " " ■'■';'." MichaelHuggins (AFRL) i*
"■
L' ,»"j!^^ •£ - _
"*
CCC
-t^) ^ J5
Dr. Don Woodbury, Dr. Arthur Morrish (DARPA) Dr. Michael Herman (AFOSR)
Inorganic Division - Main Group Chcmisify, 227'" Nalionai ACS Meeling, Anaheim-CA. April 1, 2004 .Approved forpubiic release, distribution unlirniled
BACKUP
Inorganic Division - Main Group Chemislry, 227"^ Nalionai ACS Meeting, Anaheim-CA, April 1, 2004 Approved for public release, dislribuHon unlimited
25
%^ J ^^ •
Recipe for Synthesizing Neutral Potynitrogen Compounds PolynitroQen ComDounds
m
^ •f^'^^ W^
Combine a polynitrogen cation with a polynitrogen anion to form a neutral polynitrogen compound. N/
+
N x+y
N;
ONLY TWO STABLE POLYNITOGEN IONS KNOWN TO EXIST IN BULK Cation
Anion 0=0=0
N5+ cation
-..,-
(discovered in 1999, AFRL, Christe)
Nj- snion
(discovered in 1890, Curtius)
Inorjanic Division - Main Group Chemislry. 227" National ACS MeeSng, Anaheim-CA, April 1, 2004 Approved for public release, dislribmion unlimited
%fc^ ^P'^ode I... Generation of ttie starting ^^ material
1,2-DCE
Ph4MCl
+
SbClj
"
[Ph4M][SbCl6] M = P,As
0
Cl Cli.
sb-; Cl*
..■''
,.ci' "Cl
Cl April 1. 2004
Inorganic Division - Main Group Chemistry. 227'*' Nalional ACS Msering, Anaheim-CA. April 1. 2004 ^^ Approved for public release, distribution unlimited
^0
4 M Episode II.. ..cis- or trans- disubstitution |^ ^^ with azide groups? i^J a CIi Cl'
N, Clu,
^
„.C1
'1.,
Cl*
•Cl
N,
N, trans-'isomer
April 1,2004
1
Inorganic Division - Mam Group Chemistry, 227* Nalronal ACS Meeting, Anaheim-CA. Apnl 1, 20O4 Approved for public release, distribution unlimited
J^ Episode III...Substitution of 3''' chlorine.. far*., or nr mermar- isomer lef^smai- ??? OOO lac-
^S^iH^
mer-SbCI^N^)^ April 1, 200d
fac-SbCls(N^3
Inorganic Division - Main Group Chemistry, 227" National ACS Meeting, Anahelm-OA, April 1, 2004 Approved for public release, distribution unlimited
%.j^ Episode VI...CompIete substitution of C^ ^^ ctilorine atoms X^^ T'
No crystal structure obtained yet. However, IR and Raman spectroscopy shows that Sb-Cl bonds are absent i.e., complete substitution by the azide groups.
N3
1
N3
e
-N3'
;s N.
*N, N,
ADril 1 PfWd ^ ' ■
s
l"°'9ani National ACS Meeting. Analieim-CA. April 1.2004 Approved for public release, distribution unlimited
A^^: 5:^5^