2,5-Dichlorolichexanthone

Molten mixtures of XeF6 and CrVI OF4 react by means of F2 elimination to form [XeF5 ][Xe2 F11 ][CrV OF5 ]⋅2 CrVI OF4 , [XeF5 ]2 [CrIV F6 ]⋅2 CrVI OF4 , [Xe2 F11 ]2 [CrIV F6 ], and [XeF5 ]2 [CrV 2 O2 F8 ], whereas their reactions in anhydrous hydrogen fluoride (aHF) and CFCl3 /aHF yield [XeF5 ]2 [CrV 2 O2 F8 ]⋅2 HF and [XeF5 ]2 [CrV 2 O2 F8 ]⋅2 XeOF4 . Other than [Xe2 F11 ][MVI OF5 ] and [XeF5 ][MVI 2 O2 F9 ] (M=Mo or W), these salts are the only Group 6 oxyfluoro-anions known to stabilize noble-gas cations. Their reaction pathways involve redox transformations that give [XeF5 ]+ and/or [Xe2 F11 ]+ salts of the known [CrV OF5 ]2- and [CrIV F6 ]2- anions, and the novel [CrV 2 O2 F8 ]2- anion. A low-temperature Raman spectroscopic study of an equimolar mixture of solid XeF6 and CrOF4 revealed that [Xe2 F11 ][CrVI OF5 ] is formed as a reaction intermediate. The salts were structurally characterized by LT single-crystal X-ray diffraction and LT Raman spectroscopy, and provide the first structural characterizations of the [CrV OF5 ]2- and [CrV 2 O2 F8 ]2- anions, where [CrV 2 O2 F8 ]2- represents a new structural motif among the known oxyfluoro-anions of Group 6. The X-ray structures show that [XeF5 ]+ and [Xe2 F11 ]+ form ion pairs with their respective anions by means of Xe- - -F-Cr bridges. Quantum-chemical calculations were carried out to obtain the energy-minimized, gas-phase geometries and the vibrational frequencies of the anions and their ion pairs and to aid in the assignments of their Raman spectra.

In the title compound, C19H17Cl2N3O2, there are three mol-ecules (A, B and C) in the asymmetric unit and each differs in the conformation adopted. As a result of steric repulsion, the amide group is rotated with respect to both the dichloro-phenyl and 2,3-dihydro-1H-pyrazol-4-yl rings, making dihedral angles of 44.5 (2) and 56.2 (2)°, respectively in A, 51.1 (2) and 54.1 (2)° in B, and 53.8 (2) and 54.6 (2)° in C. The dihedral angles between the dichloro-phenyl and 2,3-dihydro-1H-pyrazol-4-yl rings are 54.8 (2), 76.2 (2) and 77.5 (2)° in mol-ecules A, B and C, respectively, while the 2,3-dihydro-1H-pyrazol-4-yl and phenyl rings make dihedral angles of 45.3 (2), 51.2 (2) and 42.8 (2)°, respectively. In the crystal, two of the mol-ecules are linked through N-H⋯O hydrogen bonding to an adjoining mol-ecule, forming dimers of the R2(2)(10) type, while the third mol-ecule forms such dimers with itself. C-H⋯O inter-actions link the dimers.

The title salt, C(20)H(42)N(4)S(2) (2+)·2ClO(4) (-), was obtained from the reaction of bis-(diethyl-amino)-carbeniumdithio-carboxyl-ate, (Et(2)N)(2)C(2)S(2), with Fe(ClO(4))(2)·6H(2)O in CH(2)Cl(2). The title compound, in which one of the S atoms of (Et(2)N)(2)C(2)S(2) is bound to a 1,1-bis-(diethyl-amino)-ethane moiety, has two carbenium C atoms, and the charge compensation is provided by two perchlorate anions. The N(2)C-CS(2) bond length is 1.512 (4) Å, corresponding to a C-C single bond, and the dihedral angle between N(2)C- and -CS(2) planes [72.0 (2)°] is smaller than that of (Et(2)N)(2)C(2)S(2) [82.0 (1)°]. The crystal structure features C-H⋯S hydrogen bonds.