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1.
Forensic Sci Res ; 7(3): 566-575, 2022.
Article in English | MEDLINE | ID: mdl-36353332

ABSTRACT

Malaysia Airlines flight 17 crashed on 17 July 2014 while flying over an area of armed conflict in eastern Ukraine. The first forensic trace evidence was collected after the human remains were transferred to a safe location in the Netherlands for identification and repatriation. Disaster victim identification processes were therefore undertaken in concert with the forensic investigation. Prior to these processes, X-ray and computed tomography scanners were used to reveal foreign objects in the human remains, and a large number of these fragments were recovered after the forensic triage. A distinct group of metal fragments was identified as being potential remnants of high-energy foreign objects. Forensic analysis revealed that they were explosively deformed unalloyed steel fragments, some of which had shapes consistent with pre-formed metal fragments found in a 9N314M warhead used in Buk SA-11 missiles. Furthermore, thin film deposits of cockpit glass and aluminium were identified on the most heavily deformed side of some of the explosively deformed metal fragments, suggesting they came from outside the airplane. These findings supported early suspicions that Malaysia Airlines flight 17 was struck by a Buk SA-11 missile. KeypointsA multidisciplinary approach for combined identification and forensic investigation of human remains after a mass fatality incident.The combined use of complementary X-ray techniques for detection and provisional characterization of foreign objects in human remains.The use of sensitive and highly discriminative state of the art techniques for analysing foreign objects recovered from human remains.

2.
J Am Chem Soc ; 124(18): 5139-53, 2002 May 08.
Article in English | MEDLINE | ID: mdl-11982379

ABSTRACT

A systematically varied series of tetrahedral clusters involving ligand and core metal variation has been examined using crystallography, Raman spectroscopy, cyclic voltammetry, UV-vis-NIR and IR spectroelectrochemistry, and approximate density functional theory, to assess cluster rearrangement to accommodate steric crowding, the utility of metal-metal stretching vibrations in mixed-metal cluster characterization, and the possibility of tuning cluster electronic structure by systematic modification of composition, and to identify cluster species resultant upon electrochemical oxidation or reduction. The 60-electron tetrahedral clusters MIr(3)(CO)(11-x)(PMe(3))(x)(eta(5)-Cp) [M = Mo, x = 0, Cp = C(5)H(4)Me (5), C(5)HMe(4) (6), C(5)Me(5) (7); M = W, Cp = C(5)H(4)Me, x = 1 (13), x = 2 (14)] and M(2)Ir(2)(CO)(10-x)(PMe(3))(x)(eta(5)-Cp) [M = Mo, x = 0, Cp = C(5)H(4)Me (8), C(5)HMe(4) (9), C(5)Me(5) (10); M = W, Cp = C(5)H(4)Me, x = 1 (15), x = 2 (16)] have been prepared. Structural studies of 7, 10, and 13 have been undertaken; these clusters are among the most sterically encumbered, compensating by core bond lengthening and unsymmetrical carbonyl dispositions (semi-bridging, semi-face-capping). Raman spectra for 5, 8, WIr(3)(CO)(11)(eta(5)-C(5)H(4)Me) (11), and W(2)Ir(2)(CO)(10)(eta(5)-C(5)H(4)Me)(2) (12), together with the spectrum of Ir(4)(CO)(12), have been obtained, the first Raman spectra for mixed-metal clusters. Minimal mode-mixing permits correlation between A(1) frequencies and cluster core bond strength, frequencies for the A(1) breathing mode decreasing on progressive group 6 metal incorporation, and consistent with the trend in metal-metal distances [Ir-Ir < M-Ir < M-M]. Cyclic voltammetric scans for 5-15, MoIr(3)(CO)(11)(eta(5)-C(5)H(5)) (1), and Mo(2)Ir(2)(CO)(10)(eta(5)-C(5)H(5))(2) (3) have been collected. The [MIr(3)] clusters show irreversible one-electron reduction at potentials which become negative on cyclopentadienyl alkyl introduction, replacement of molybdenum by tungsten, and replacement of carbonyl by phosphine. These clusters show two irreversible one-electron oxidation processes, the easier of which tracks with the above structural modifications; a third irreversible oxidation process is accessible for the bis-phosphine cluster 14. The [M(2)Ir(2)] clusters show irreversible two-electron reduction processes; the tungsten-containing clusters and phosphine-containing clusters are again more difficult to reduce than their molybdenum-containing or carbonyl-containing analogues. These clusters show two one-electron oxidation processes, the easier of which is reversible/quasi-reversible, and the more difficult of which is irreversible; the former occur at potentials which increase on cyclopentadienyl alkyl removal, replacement of tungsten by molybdenum, and replacement of phosphine by carbonyl. The reversible one-electron oxidation of 12 has been probed by UV-vis-NIR and IR spectroelectrochemistry. The former reveals that 12(+) has a low-energy band at 8000 cm(-1), a spectrally transparent region for 12, and the latter reveals that 12(+) exists in solution with an all-terminal carbonyl geometry, in contrast to 12 for which an isomer with bridging carbonyls is apparent in solution. Approximate density functional calculations (including ZORA scalar relativistic corrections) have been undertaken on the various charge states of W(2)Ir(2)(CO)(10)(eta(5)-C(5)H(5))(2) (4). The calculations suggest that two-electron reduction is accompanied by W-W cleavage, whereas one-electron oxidation proceeds with retention of the tetrahedral core geometry. The calculations also suggest that the low-energy NIR band of 12(+) arises from a sigma(W-W) --> sigma*(W-W) transition.

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