Fingerprint and Inkjet-trace Imaging using Disulfur Dinitride
Kelly et. al. Chemical Communications
Slide 2
? ? ? ? ? ? Forensics and Fingerprints o Why Fingerprints? o
Fingerprint Detection o Fingerprint Formation o Powder dusting o
Ninhydrin reaction o Lawsone reaction o Multi-metal deposition
Sodhi, G.S., Kaur, J. Fingermarks detection by eosin-blue dye,
Forensics International, 2001, 115, 69-71 Zhang et. al. SECM
imaging of MMD-enhanced latent fingermarks, Chem Comm, 2007,
3948-3950 Jelly et. al., Lawsone: a novel reagent for the detection
of latent fingermarks on paper surfaces, Chem Comm, 2008, 3513-3515
Kelly et. al. Fingerprint and inkjet-trace imaging using disulfur
dinitride, Chem Comm, 2008, 6111-6113
http://www.forensi-tech.com/products/technotes/graphics/1-2720_min.jpg
Slide 3
Fingerprints and Disulfur Dinitride (S 2 N 2 ) o Surfaces/Media
o Non-invasive to evidence o Clear images o Short developing time o
Quality of fingerprints Kelly et. al. Fingerprint and inkjet-trace
imaging using disulfur dinitride, Chem Comm, 2008, 6111-6113
Slide 4
Properties of Disulfur Dinitride o Structure o Cyclic square
planar o 6 -electron system o Diradical o Physical Characteristics
o Color o Explosive Bond Lengths = 1.74 S-N, 1.54 S=N Bond Lengths
= 1.64 S=N Mikulski, C.M. et. al. Synthesis and structure of
metallic polymeric sulfur nitride (SN) x and its precursor,
disulfur dinitride, S 2 N 2, Journal of the American Chemical
Society, 1975, 6358-6363 Mueller, H. et. al. In situ, time-resolved
x-ray diffraction study of the solid-state polymerization of
disulfur dinitride to poly(sulfur nitride), Inorg. Chem., 1996, 36,
1488-1494 Banister, A.J., Gorrell, I.B. Poly(sulfur nitride): The
first polymeric metal, Adv. Mater., 1998, 10, 1415-1429 Chivers,
Tristram. A Guide to Chalcogen-Nitrogen Chemistry, World
Scientific, 2005, 53-55
Slide 5
Polymerization of S 2 N 2 to polythiazyl (SN) x 1 2 3 4
Mikulski, C.M. et. al. Synthesis and structure of metallic
polymeric sulfur nitride (SN) x and its precursor, disulfur
dinitride, S 2 N 2, Journal of the American Chemical Society, 1975,
6358-6363 Chivers, Tristram. A Guide to Chalcogen-Nitrogen
Chemistry, World Scientific, 2005, 53-55 Mueller, H. et. al. In
situ, time-resolved x-ray diffraction study of the solid-state
polymerization of disulfur dinitride to poly(sulfur nitride),
Inorg. Chem., 1996, 36, 1488-1494 106.2 119.9 1.59 1.63
Slide 6
Properties of Polythiazyl (SN) x o Anisotropic Crystal o
Polymeric Metal Mikulski, C.M. et. al. Synthesis and structure of
metallic polymeric sulfur nitride (SN) x and its precursor,
disulfur dinitride, S 2 N 2, Journal of the American Chemical
Society, 1975, 6358-6363 Mueller, H. et. al. In situ, time-resolved
x-ray diffraction study of the solid-state polymerization of
disulfur dinitride to poly(sulfur nitride), Inorg. Chem., 1996, 36,
1488-1494 Banister, A.J., Gorrell, I.B. Poly(sulfur nitride): The
first polymeric metal, Adv. Mater., 1998, 10, 1415-1429 Chivers,
Tristram. A Guide to Chalcogen-Nitrogen Chemistry, World
Scientific, 2005, 53-55 o Orientation o Polarized Light o Electron
Arrangement
Slide 7
Properties of Polythiazyl (SN) x o Conductivity o Solid-state
devices o Electrodes o Stability o Electronegativity Mikulski, C.M.
et. al. Synthesis and structure of metallic polymeric sulfur
nitride (SN) x and its precursor, disulfur dinitride, S 2 N 2,
Journal of the American Chemical Society, 1975, 6358-6363 Mueller,
H. et. al. In situ, time-resolved x-ray diffraction study of the
solid-state polymerization of disulfur dinitride to poly(sulfur
nitride), Inorg. Chem., 1996, 36, 1488-1494 Banister, A.J.,
Gorrell, I.B. Poly(sulfur nitride): The first polymeric metal, Adv.
Mater., 1998, 10, 1415-1429 Chivers, Tristram. A Guide to
Chalcogen-Nitrogen Chemistry, World Scientific, 2005, 53-55
Slide 8
Importance o Applications o Forensics o Fingerprints o
Inkjet-trace imaging
http://www.rsc.org/chemistryworld/News/2007/July/13070701.asp
Slide 9
Techniques Starting Material ConditionsProduct S 4 N 4 Thermal
cracking Microcrystalline over silver woolpolymer [S 5 N 5 ] +
Electrolysis in Microcrystalline sulfur dioxide or polymer
acetonitrile (NSCl) 3 & Acetonitrile at Powdered trimethylsilyl
azide - 15 C polymer Banister, A.J., Gorrell, I.B. Poly(sulfur
nitride): The first polymeric metal, Adv. Mater., 1998, 10,
1415-1429 Chivers, Tristram. A Guide to Chalcogen-Nitrogen
Chemistry, World Scientific, 2005, 53-55 Kelly et. al., Rapid
polymerization of S 2 N 2 within Na-ZSM-f channels, Chem Comm,
2007, 4812-4814
Slide 10
Experimental Rapid polymerization of S 2 N 2 within Na-ZSM-5
channels Kelly et. al.Polymerization of S 2 N 2 to (SN) x General
Experimental Mueller et. al., In situ, time-resolved x-ray
diffraction study of the solid-state polymerization of disulfur
dinitride t poly (sulfur nitride), Inorg Chem, 1996, 36,
1488-1494
Slide 11
Results o S 2 N 2 (SN) x o Zeolite o Conductivity o Glassware
Na-ZSM-5 after S 2 N 2 exposure (SN) x Kelly et. al., Rapid
polymerization of S 2 N 2 within Na-ZSM-f channels, Chem Comm,
2007, 4812- 4814
Slide 12
Investigation of S 2 N 2 vapours on fingerprints o Materials o
Fingerprints o Qualitative o Quantitative Growth on fingerprints
(SN) x Kelly et. al.,Fingerprint and inkjet-trace Imaging using
disulfur dinitride, Chem Comm, 2008, 6111-6113
Slide 13
Conclusions o Polymerization o Fingerprints o Forensics o
Positives o Negatives Kelly et. al.,Fingerprint and inkjet-trace
Imaging using disulfur dinitride, Chem Comm, 2008, 6111-6113
http://www.rsc.org/chemistryworld/News/2007/July/13070701.asp
Slide 14
Investigation of S 2 N 2 vapours on inkjet o Materials o
Preparation o Mechanism o Qualitative o Quantitative Kelly et.
al.,Fingerprint and inkjet-trace Imaging using disulfur dinitride,
Chem Comm, 2008, 6111-6113
