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Fingerprint and Inkjet-trace Imaging using Disulfur Dinitride Kelly et. al. Chemical Communications

Fingerprint and Inkjet-trace Imaging using Disulfur Dinitride Kelly et. al. Chemical Communications. Forensics and Fingerprints. ?. Why Fingerprints?. ?. Fingerprint Formation. ?. Fingerprint Detection. Powder dusting. ?. Ninhydrin reaction. ?. ?. Lawsone reaction.

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Fingerprint and Inkjet-trace Imaging using Disulfur Dinitride Kelly et. al. Chemical Communications

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  1. Fingerprint and Inkjet-trace Imaging using DisulfurDinitride Kelly et. al. Chemical Communications

  2. Forensics and Fingerprints ? • Why Fingerprints? ? • Fingerprint Formation ? • Fingerprint Detection • Powder dusting ? • Ninhydrin reaction ? ? • Lawsone reaction 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, ChemComm, 2007, 3948-3950 Jelly et. al., Lawsone: a novel reagent for the detection of latent fingermarks on paper surfaces, ChemComm, 2008, 3513-3515 Kelly et. al. Fingerprint and inkjet-trace imaging using disulfurdinitride, ChemComm, 2008, 6111-6113 http://www.forensi-tech.com/products/technotes/graphics/1-2720_min.jpg • Multi-metal deposition

  3. Fingerprints and DisulfurDinitride (S2N2) • Surfaces/Media • Non-invasive to evidence • Clear images • Short developing time • Quality of fingerprints Kelly et. al. Fingerprint and inkjet-trace imaging using disulfurdinitride, ChemComm, 2008, 6111-6113

  4. Properties of DisulfurDinitride • Structure • Cyclic square planar • 6 π-electron system Bond Lengths = 1.74 S-N, 1.54 S=N Bond Lengths = 1.64 S=N • Diradical • Physical Characteristics • Color • Explosive Mikulski, C.M. et. al. Synthesis and structure of metallic polymeric sulfur nitride (SN)x and its precursor, disulfurdinitride, S2N2, 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 disulfurdinitride 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

  5. Polymerization of S2N2 to polythiazyl (SN)x 1 2 3 119.9˚ 1.59 Å 106.2˚ 4 1.63 Å Mikulski, C.M. et. al. Synthesis and structure of metallic polymeric sulfur nitride (SN)x and its precursor, disulfurdinitride, S2N2, 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 disulfurdinitride to poly(sulfur nitride), Inorg. Chem., 1996, 36, 1488-1494

  6. Properties of Polythiazyl (SN)x • Anisotropic Crystal • Orientation • Polarized Light • “Polymeric Metal” • Electron Arrangement Mikulski, C.M. et. al. Synthesis and structure of metallic polymeric sulfur nitride (SN)x and its precursor, disulfurdinitride, S2N2, 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 disulfurdinitride 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

  7. Properties of Polythiazyl (SN)x • Conductivity • Electronegativity • Solid-state devices • Electrodes • Stability Mikulski, C.M. et. al. Synthesis and structure of metallic polymeric sulfur nitride (SN)x and its precursor, disulfurdinitride, S2N2, 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 disulfurdinitride 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

  8. Importance • Applications • Forensics • Fingerprints • Inkjet-trace imaging http://www.rsc.org/chemistryworld/News/2007/July/13070701.asp

  9. Techniques S4N4 Thermal cracking Microcrystalline over silver wool polymer [S5N5]+ Electrolysis in Microcrystalline sulfur dioxide or polymer acetonitrile (NSCl)3 & Acetonitrile at Powdered trimethylsilylazide - 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 S2N2 within Na-ZSM-f channels, ChemComm, 2007, 4812-4814

  10. Experimental Rapid polymerization of S2N2 within Na-ZSM-5 channels – Kelly et. al. Polymerization of S2N2 to (SN)x – General Experimental Mueller et. al., In situ, time-resolved x-ray diffraction study of the solid-state polymerization of disulfurdinitride t poly (sulfur nitride), InorgChem, 1996, 36, 1488-1494

  11. Results • S2N2 (SN)x • Zeolite • Conductivity • Glassware Na-ZSM-5 after S2N2 exposure (SN)x Kelly et. al., Rapid polymerization of S2N2 within Na-ZSM-f channels, ChemComm, 2007, 4812-4814

  12. Investigation of S2N2 vapours on fingerprints • Materials • Fingerprints • Qualitative Growth on fingerprints • Quantitative (SN)x Kelly et. al.,Fingerprint and inkjet-trace Imaging using disulfurdinitride, ChemComm, 2008, 6111-6113

  13. Conclusions • Polymerization • Fingerprints • Forensics • Positives • Negatives Kelly et. al.,Fingerprint and inkjet-trace Imaging using disulfurdinitride, ChemComm, 2008, 6111-6113 http://www.rsc.org/chemistryworld/News/2007/July/13070701.asp

  14. Investigation of S2N2 vapours on inkjet • Materials • Preparation • Mechanism • Qualitative • Quantitative Kelly et. al.,Fingerprint and inkjet-trace Imaging using disulfurdinitride, ChemComm, 2008, 6111-6113

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