Deepak Chand,1 Lauren A. Mitchell,2 Damon A. Parrish,2 and Jean’ne M. Shreeve1* 1Department of Chemistry, University of Idaho, Moscow, Idaho, 83844-2343, United States

2Naval Research Laboratory, Code 6030, Washington, D.C. 20375-5001, United States.

Introduction

Synthesis of polyiodo compounds

Acknowledgment

The authors are grateful for the support of ONR (NOOO14-12-1-0536), and the

Defense Threat Reduction Agency (HDTRA1–11–1–0034 ).

References 1. Chand, D.; Shreeve, J. M; Chem. Commun. 2015, 51, 3438-3441.

2. Electrophilic iodination: A gateway to biocides and energetic materials; ( Manuscript

submitted to Angew. Chem. Int. Ed.)

3. Rahman, M. A; Shito, F.; Kitamura, T.; Synthesis. 2010, 27-29.

Versatile Polyiodopyrazoles: Synthesis and Biocidal Promise

Chemical and biological weapons possess huge destruction potential and pose considerable potential public threat. There is an estimate that deaths in millions could occur following the release of

only 100 kg of anthrax. As a result, interest in developing Agent Defeat Weapons (ADWs) has grown remarkably during the last few years. ADWs are airborne warheads which contain anti-bioagent

materials, such as iodine-rich compounds that form large amounts of elemental iodine, and hydroiodic acid (HI) as detonation products that have biocidal properties. In order to be a suitable ADW

feed, easily containable, non sublimable, and thermally stable sources of biocides are required. Polyiodopyrazoles can be good source of nonsublimable iodine. Up to nine iodine atoms were

introduced into a single molecule (13) in a one-pot reaction using trifluoroperacetic acid-mediated electrophilic iodination. The scope of this reaction was investigated extensively using diverse

pyrazole substrates. Detonation properties and detonation products are predicted by employing Cheetah 6.0. These compounds exhibit low detonation velocity and low detonation pressure. The

calculated (Cheetah 6.0) gas phase detonation products, were I2 and, in some cases, HI and I.

[M]+

[M]+

Table 1: Major detonation products shown by Cheetah 6.0 calculations [wt. % kg kg-1]

Figure 1: The sums of iodine-containing species in the detonation products of compounds 1,

2, 3, 4, and 5 (weight percent).

Thirteen polyiodopyrazoles including 3, 4, 5-triiodopyrazole were synthesized using

trifluoroperacetic acid mediated electrophilic iodination reaction.

Calculated detonation products and properties suggest that the compounds may be

effective bio-agent defeat agents.

These polyiodopyrazoles may have application not only as Agent Defeat Weapons but

also to other areas such as medicinal chemistry, materials science and synthetic

organic chemistry

Structure of 13

Crystal structure of 4

Crystal structure of 11

Comp N2 [g] I2 [g] HI [g] I [g] C [s]

1 6.22 52.1 22.87 10.34 8.00

2 6.09 81.9 - - 8.51

3 3.93 88.6 - - 6.34

4 22.2 49.6 - - 8.36

5 18.8 41.7 - - 5.07

Benzene based polyiodo pyrazoles

Ethylene bridged polyiodo pyrazoles

Introduction

Conclusions