Darstellung, Kristallstrukturen und Schwingungsspektren von trans-[Pt(N3)4X2]2, X = Cl, Br, I (2000)

Durch oxidative Addition an (n-Bu4N)2[Pt(N3)4] mit den elementaren Halogenen in Dichlormethan entstehen trans-(n-Bu4N)2[Pt(N3)4X2], X = Cl, Br, I. Röntgenstrukturanalysen an Einkristallen von trans-(Ph4P)2[Pt(N3)4Cl2] (triklin, Raumgruppe P1, a = 10,352(1), b = 10,438(2), c = 11,890(2) Å, α = 91,808(12), β = 100,676(12), γ = 113,980(10)°, Z = 1), trans-(Ph4P)2[Pt(N3)4Br2] (triklin, Raumgruppe P1, a = 10,336(1), b = 10,536(1), c = 12,119(2) Å, α = 91,762(12), β = 101,135(12), γ = 112,867(10)°, Z = 1) und trans-(Ph4P)2[Pt(N3)4I2] (triklin, Raumgruppe P1, a = 10,186(2), b = 10,506(2), c = 12,219(2) Å, α = 91,847(16)°, β = 101,385(14), γ = 111,965(18), Z = 1) zeigen, daß die Verbindungen isotyp kristallisieren und die oktaedrischen Komplexanionen inversionssymmetrisch sind. Die Bindungslängen betragen Pt–Cl = 2,324, Pt–Br = 2,472, Pt–I = 2,619 und Pt–N = 2,052–2,122 Å. Die Azidoliganden sind unter Pt–Nα–Nβ-Winkeln von 116,2–121,9° gebunden und mit Nα–Nβ–Nγ-Winkeln von 172,1–176,8° nahezu linear. In den Schwingungsspektren beobachtet man die Platin-Halogen-Valenzschwingungen von trans-(n-Bu4N)2[Pt(N3)4X2] im Bereich von 327–337 (X = Cl), bei 202 (Br) und bei 145–165 cm–1 (I), die Platin-Azid-Valenzschwingungen der drei Komplexsalze liegen bei 401–421 cm–1. Unter Verwendung der röntgenographisch ermittelten Molekülparameter lassen sich die Schwingungsspektren durch Normalkoordinatenanalyse zuordnen. Die Valenzkraftkonstanten betragen fd(PtCl) = 1,90, fd(PtBr) = 1,64, fd(PtI) = 1,22, fd(PtNα) = 2,20–2,27 und fd(NαNβ, NβNγ) = 12,44 mdyn/Å. Synthesis, Crystal Structures, and Vibrational Spectra of trans-[Pt(N3)4X2]2–, X = Cl, Br, I By oxidative addition to (n-Bu4N)2[Pt(N3)4] with the elemental halogens in dichloromethane trans-(n-Bu4N)2[Pt(N3)4X2], X = Cl, Br, I are formed. X-ray structure determinations on single crystals of trans-(Ph4P)2[Pt(N3)4Cl2] (triclinic, space group P1, a = 10.352(1), b = 10.438(2), c = 11.890(2) Å, α = 91.808(12), β = 100.676(12), γ = 113.980(10)°, Z = 1), trans-(Ph4P)2[Pt(N3)4Br2] (triclinic, space group P1, a = 10.336(1), b = 10.536(1), c = 12.119(2) Å, α = 91.762(12), β = 101.135(12), γ = 112.867(10)°, Z = 1) and trans-(Ph4P)2[Pt(N3)4I2] (triclinic, space group P1, a = 10.186(2), b = 10.506(2), c = 12.219(2) Å, α = 91.847(16), β = 101.385(14), γ = 111.965(18)°, Z = 1) reveal, that the compounds crystallize isotypically with octahedral centrosymmetric complex anions. The bond lengths are Pt–Cl = 2.324, Pt–Br = 2.472, Pt–I = 2.619 and Pt–N = 2.052–2.122 Å. The approximate linear Azidoligands with Nα–Nβ–Nγ-angles = 172.1–176.8° are bonded with Pt–Nα–Nβ-angles = 116.2–121.9°. In the vibrational spectra the platinum halogen stretching vibrations of trans-(n-Bu4N)2[Pt(N3)4X2] are observed in the range of 327–337 (X = Cl), at 202 (Br) and in the range of 145–165 cm–1 (I), respectively. The platinum azide stretching modes of the three complex salts are in the range of 401–421 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(PtCl) = 1.90, fd(PtBr) = 1.64, fd(PtI) = 1.22, fd(PtNα) = 2.20–2.27 and fd(NαNβ, NβNγ) = 12.44 mdyn/Å.