The Cl₂O₂⁺ Cation:  Preparation and Structural Investigation of Cl₂O₂⁺SbF₆^- and Cl₂O₂⁺Sb₂F₁₁^-

Abstract

Cl2 reacts with O2 +SbF6 - in anhydrous HF, forming subsequently a violet, a blue, and a yellow solution. Crystals from the violet solution are identified as Cl2O2 +SbF6 - or Cl2O2 +Sb2F11 - by means of single-crystal structural determinations, Raman spectroscopy, magnetic and EPR measurements, and ab initio calculations. The cation has a planar trapezoid structure with Cl−Cl distances of 190.9(1)−191.6(5) pm, O−O distances of 118.5(11)−120.7(5) pm, and Cl−O distances of 240.8(4)−242.8(4) pm. The bonding between the two parts of the cation may be described as a π*−π* interaction, resulting in a charge transfer of about 0.6 electrons with respect to isolated Cl2 + and O2 fragments. The bonding of O2 to Cl2 + is reversible, as is shown by 18O isotope exchange. The nature of the blue solution remains unknown. Both deeply colored compounds turn into yellow Cl3 + if warmed to room temperature, especially in the presence of excess Cl2. The Cl3 + cation is symmetrical and bent with Cl−Cl = 197.23−199.44 pm and Cl−Cl−Cl = 104.51(10)−105.62(7)°.

Isomeric Cl2O2+ and Cl2O2− ions

“…These findings are consistent with the results of computational studies at the CASPT 2 14 and G2 12 levels of theory concerning the energetics of the least endothermic dissociation processes of the Cl 2 O 2 isomers of interest:…”

“…[3][4][5][6][7][8][9][10][11][12] By contrast, very little is known of the corresponding charged species, except for the experimental measurement of the ionization potential of ClOOCl 13 and a theoretical study of the Cl 2 O 2 Á isomers at the G2 level. 12 Recently, (Cl 2 O 2 ) SbF 6 À and (Cl 2 O 2 ) Sb 2 F 11 À salts have been prepared and characterized in the solid phase by single-crystal diffractometry, 14 underlining the growing interest in the ionic chemistry of Cl 2 O 2 . As an extension of our continuing interest in charged halogenated species of potential atmospheric relevance, 15 involving the trichlorinium ion, abundant in the Cl 2 plasma.…”

Structures, Vibrational Frequencies, and Stabilities of Halogen Cluster Anions and Cations, Xn+/–, n = 3, 4, and 5

“…116 − ] X-ray crystal structures by only 2 to 3°, and the Cl−Cl bond lengths are in good agreement with experiment. 29 The experimental solid state angles 17,29,37 of Cl 3 + , Br 3 + , and I 3 + are about 3°less than those predicted at the CCSDT(T)/ATZ level.…”

Stable Radicals of the Heavy p‐Block Elements

“…The source of the intriguing paramagnetic species 49 is the reaction between chlorine (Cl 2 ) and an [O 2 ] + salt with either [SbF 6 ] − or [Sb 2 F 11 ] − as the counter ion. 66 Similar to the dimer [I 4 ] 2+ , the structure of 49 is a planar trapezium with short bonds within the Cl 2 and O 2 units (1.909(1) and 1.207(5)Å, respectively), and a long Cl-O distance (about 2.41Å) between these two units, cf. the sum of van der Waals radii for Cl and O = 3.30Å.…”

“…Consistently, the EPR spectrum of 49 (Figure 10.7b) shows a seven-line pattern (g = 1.9988) due to the coupling of the unpaired electron with two equivalent chlorine centers (a( 35/37 Cl) = 2.23 G; 35 Cl, I = 3 / 2 , 75.8 %; 37 Cl, I = 3 / 2 , 24.2 %). 66 Subsequent attempts to produce the monomeric radical cation [Cl 2 ] •+ from the reaction between Cl 2 and IrF 6 also resulted in a dimeric product in the form of the rectangular radical cation [(Cl 2 ) 2 ] •+ (50) (Figure 10.7c). 67 The structure of 50 displays two short Cl-Cl bonds and two long Cl· · · Cl contacts (1.941(3) and 2.936(7)Å, respectively).…”