Propellanes LXXIX. Comparison of the geometries of dithia[n.3.3]propellanes (n = 1, 2, 3) and dithia(and oxathia)[4.3.3]propellanes. Study of the influence of complexation with HgCl₂, I₂, CdCl₂ and PdCl₂ and of formation of sulfoxides on some of these compounds. Demonstration of the 'Klammer' effect. Structures of eighteen crystals

Abstract

The room-temperature crystal structures of eighteen compounds are reported. (2) symmetry. There are only three exceptions to this non-mixing rule among thirty-odd of the many propellane structures reported in the literature. The considerable deviations found from ideal conformations are ascribed to crystal packing effects and, for molecules with n = 1 and 2, to the deviations from tetrahedrality at the bridgehead atoms; this serves to explain the 'Klammer' effect. The lowest-energy conformations from molecular-mechanics calculations are generally those found experimentally.

Synthesis and Structural Characterization of Metal Complexes of 2-Formylpyrrole-4N-ethylthiosemicarbazone (4 EL1) and 2-Acetylpyrrole-4N-ethylthiosemicarbazone (4 EL2)

“…In 7, the Hg±S distance and the distance between the mercury and non-bridging Cl atom are slightly shorter than in complexes of mercury chloride with N,S-didentate [26] or N,N,S-tridentate [24,25,27] thiosemicarbazones, but are similar to those found in other dimeric mercury chloride complexes with S-monodentate thiosemicarbazone ligands [28,29]. Of the distances between the mercury atom and bridging chlorine atoms, the shortest two are significantly shorter than in other chloro-bridged Hg dimers with S-monodentate ligands [28,32], while the longest two are at least 0.2 A Ê longer than in any other known dimer of this kind [28,30,31] (in those with long Hg±Cl br distances most closely approaching those of 7 the mercury atoms have coordination number five, like 7 [32]). …”

Structural and theoretical study on the 1:2 addition complex of 1,2,4,5-bis{8′,11′-dithia[4.3.3]propella(3′,4′)}benzene with I2

“…The length of the conjoining bond, C(5)-C(6), with the value of 1.580(5) Å, is significantly longer than that of a typical single C-C bond, but comparable to average (C) 3 -C(sp 3 )-C(sp 3 )-(C) 3 (1.588 Å, [99]). Among the known dithia-and oxathia [4.3.3] propellanes only those with the rigid conformations: boat for 6-membered rings and envelope for 5-membered rings, show such an elongated conjoining bond (1.570-1.588 Å) [8,9].…”

“…Dithia-and oxathiapropellanes were also a subject of structural investigations, both propellanes themselves and their complexes with Cl 2 Á4H 2 O, I 2 , HgCl 2 , CdCl 2 and PdCl 2 [8]. One example of oxathia propellane, obtained by Diels-Alder reaction, was also described by Kaftory [9].…”

Reactions Between Chalcogen Donors and Dihalogens/Interalogens: Typology of Products and Their Characterization by FT‐Raman Spectroscopy

“…For and adducts, which are strong adducts according to the above classifications, much less structural and FT-Raman data are available, therefore generalizations are less reliable. adducts with both - and -donors show one main peak in their FT-Raman spectra in the range 190–140 cm −1 [16, 59, 60, 62–67, 81] at a lower frequency with respect to solid [216 cm −1 , d (I−Br) = 2.521(4) Å] [98], and it is assignable to a stretching vibration of the E−I−Br three-body system having a major contribution from the ν (I−Br) vibration [63]. adducts (only four out of seven are both structurally and vibrationally characterized) [60, 67, 68] generally show in their FT-Raman spectra two main peaks: one in the range 240–180 cm −1 presumably due to the antisymmetric ( ν 3 ) stretching vibration of the E−I−Cl three body-system ( = , ), and the other at about 130 cm −1 due to the symmetric ( ν 1 ) stretching vibration (solid is characterized by a single peak at 283 cm −1 in its FT-Raman spectrum with a d (I−Cl) = 2.446(6) Å) [99].…”