Darstellung,Kristallstrukturen, Schwingungsspektren und Normalkoordinatenanalyse von trans‐(n‐Bu4N)2[Pt(ECN)2(ox)2], E = S,Se |
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| Authors: | J‐G Uttecht W Preetz |
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| Abstract: | Synthesis, Crystal Structure, Vibrational Spectra, and Normal Coordinate Analysis of trans ‐( n ‐Bu4N)4Pt(ECN)2(ox)2], E = S, Se By reaction of (n‐Bu4N)2Pt(ox)2] with (SCN)2 and (SeCN)2 in dichloromethane trans‐(n‐Bu4N)2Pt(SCN)2(ox)2] ( 1 ) und trans‐(n‐Bu4N)2Pt(SeCN)2(ox)2] ( 2 ) are formed. The crystal structures of 1 (triclinic, space group P1, a = 10.219(2), b = 11.329(2), c = 12.010(3) Å, α = 114.108(15), β = 104.797(20), γ = 102.232(20)°, Z = 1) and 2 (triclinic, space group P1, a = 10.288(1), b = 11.332(1), c = 12.048(1) Å, α = 114.391(9), β = 103.071(10), γ = 102.466(12)°, Z = 1) reveal, that the compounds crystallize isotypically with centrosymmetric complex anions. The bond lengths are Pt–S = 2.357, Pt–Se = 2.480 and Pt–O = 2.011 ( 1 ) und 2.006 Å ( 2 ). The oxalato ligands are nearly plane with O–C–C–O torsion angles of 1.7–3.6°. The via S or Se coordinated linear groups are inclined between both oxalato ligands with Pt–E–C angles of 100.4 (E = S) and 97.4° (Se). In the vibrational spectra the PtE stretching vibrations are observed at 299–314 ( 1 ) and 189–200 cm–1 ( 2 ). The PtO stretching vibrations are coupled with internal vibrations of the oxalato ligands and appear in the range of 400–800 cm–1. Based on the molecular parameters of the X‐ray determinations the IR and Raman spectra are assigned by normal coordinate analysis. The valence force constants are fd(PtS) = 1.75, fd(PtSe) = 1.35 and fd(PtO) = 2.77 mdyn/Å. The NMR shifts are δ(195Pt) = 5435.2 ( 1 ), 5373.7 ( 2 ) and δ(77Se) = 353.2 ppm with the coupling constant 1J(SePt) = 37.4 Hz. |
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| Keywords: | Platinum Crystal structure Vibrational spectroscopy NMR (195Pt 77Se) |
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