Thermal decomposition of the perfluorinated peroxides CF3OC(O)OOC(O)F and CF3OC(O)OOCF3

Gas phase thermal decomposition of CF(3)OC(O)OOC(O)F and CF(3)OC(O)OOCF(3) was studied at temperatures between 64 and 98 degrees C (CF(3)OC(O)OOC(O)F) and 130-165 degrees C (CF(3)OC(O)OOCF(3)) using FTIR spectroscopy to follow the course of the reaction. For both substances, the decompositions were studied with N(2) and CO as bath gases. The rate constants for the decomposition of CF(3)OC(O)OOC(O)F in nitrogen and carbon monoxide fit the Arrhenius equations k(N)2 = (3.1 +/- 0.1) x 10(15) exp[-(29.0 +/- 0.5 kcal mol(-1)/RT)] and k(CO) = (5.8 +/- 1.3) x 10(15) exp[-(29.4 +/- 0.5 kcal mol(-1)/RT)], and that for CF(3)OC(O)OOCF(3) fits the equation k = (9.0 +/- 0.9) x 10(13) exp[-(34.0 +/- 0.7 kcal mol(-1)/RT)] (all in units of inverted seconds). Rupture of the O-O bond was shown to be the rate-determining step for both peroxides, and bond energies of 29 +/- 1 and 34.0 +/- 0.7 kcal mol(-1) were obtained for CF(3)OC(O)OOC(O)F and CF(3)OC(O)OOCF(3). The heat of formation of the CF(3)OCO(2)(*) radical, which is a common product formed in both decompositions, was calculated by ab initio methods as -229 +/- 4 kcal mol(-1). With this value, the heat of formation of the title species and of CF(3)OC(O)OOC(O)OCF(3) could in turn be obtained as Delta(f) degrees (CF(3)OC(O)OOC(O)F) = -286 +/- 6 kcal mol(-1), Delta(f) degrees (CF(3)OC(O)OOCF(3)) = -341 +/- 6 kcal mol(-1), and Delta(f) degrees (CF(3)OC(O)OOC(O)OCF(3)) = -430 +/- 6 kcal mol(-1).     

((Fluoroformyl)imido)(trifluoromethyl)sulfur fluoride, FC(O)N = S(F)CF3: unexpected conformational properties

The geometric structure and conformational properties of ((fluoroformyl)imido)(trifluoromethyl)sulfur fluoride, FC(O)N = S(F)CF3, are investigated by gas electron diffraction (GED) experiments, IR (gas) spectroscopy, and quantum chemical calculations (HF, MP2, and B3LYP with 6-31G* basis sets). The GED intensities are reproduced best with a mixture of 79(12)% trans-syn and 21(12)% cis-syn conformers. "Trans/cis" describes the orientation around the S=N double bond (FC(O) group relative to sulfur substituents), and "syn" refers to the orientation of the C=O bond relative to the S=N bond. From the intensities of the C=O bands in the IR (gas) spectrum, a composition of 86(8)%:14(8)% is derived. These ratios correspond to delta G0(GED) = 0.79(36) and delta G0(IR) = 1.09(35) kcal mol-1. The preference of a trans structure, around the S=N double bond is unexpected, since all imidosulfur compounds studied thus far possess a cis configuration. The conformational properties are reproduced qualitatively correctly by all theoretical calculations. The predicted energy differences delta E(HF) = 2.41, delta E(MP2) = 0.64, and delta E(B3LYP) = 0.28 kcal mol-1 are larger or slightly smaller than the experimental values. Additional theoretical calculations (B3LYP) for several imidosulfur compounds reveal that only FC(O)N=S(F)CF3, with mixed substitution at sulfur and the FC(O) group bonded to nitrogen, prefers the trans structure.     

Fluorocarbonyl trifluoromethanesulfonate, FC(O)OSO2CF3: structure and conformational properties in the gaseous and condensed phases

Pure fluorocarbonyl trifluoromethanesulfonate, FC(O)OSO(2)CF(3), is prepared in about 70% yield by the ambient-temperature reaction between FC(O)SCl and AgCF(3)SO(3). The geometric structure and conformational properties of the gaseous molecule have been studied by gas electron diffraction (GED), vibrational spectroscopy [IR(gas), IR(matrix), and Raman(liquid)] and quantum chemical calculations (HF, MP2, and B3LYP with 6-311G basis sets); in addition, the solid-state structure has been determined by X-ray crystallography. FC(O)OSO(2)CF(3) exists in the gas phase as a mixture of trans [FC(O) group trans with respect to the CF(3) group] and gauche conformers with the trans form prevailing [67(8)% from GED and 59(5)% from IR(matrix) measurements]. In both conformers the C=O bond of the FC(O) group is oriented synperiplanar with respect to the S-O single bond. The experimental free energy difference between the two forms, DeltaG degrees = 0.49(13) kcal mol(-1) (GED) and 0.22(12) kcal mol(-1) (IR), is slightly smaller than the calculated value (0.74-0.94 kcal mol(-1)). The crystalline solid at 150 K [monoclinic, P2(1)/c, a = 10.983(1) A, b = 6.4613(6) A, c = 8.8508(8) A, beta = 104.786(2) degrees ] consists exclusively of the trans conformer.     

Bis(trifluoroaceto) disulfide (CF3C(O)OSSOC(O)CF3): a HeI photoelectron spectroscopy and theoretical study

Bis(trifluoroaceto) disulfide CF(3)C(O)OSSOC(O)CF(3) was prepared and studied by Raman, photoelectron spectroscopy (PES), and theoretical calculations. This molecule exhibits gauche conformation with both C=O groups cis to the S-S bond; the structure of the OSSO moiety is characterized by dihedral angle delta(OSSO) = -95.1 degrees due to the sulfur-sulfur lone pair interactions. The contracted S-S bond (1.979 Angstroms) and relatively high rotational barrier (19.29 kcal mol(-1) at the B3LYP/6-31G level) of the delta(OSSO) indicate the partial resonance-induced double bond character in this molecule. After ionization, the ground cationic-radical form of CF(3)C(O)OSSOC(O)CF(3)(*+) adopts a trans planar main-atom structure (delta(OSSO) = 180 degrees and delta(OCOS) = 0 degrees ) with C(2)(h) symmetry. The S-S bond elongates to 2.054 Angstroms, while the S-O bond shortens from 1.755 Angstroms in neutral form to 1.684 Angstroms in its corresponding cationic-radical form. The adiabatic ionization energy of 9.91 eV was obtained accordingly. The first two HOMOs correspond to the electrons mainly localized on the sulfur 3p lone pair MOs: 3ppi {36a (n(A)(S))](-1) and 3ppi [35b (n(B)(S), n(B)(O(C)(=)(O)))](-1), with an experimental energy separation of 0.16 eV. The first vertical ionization energy is determined to be 10.81 eV.     

Haloacyl complexes of boron, [(CF3)3BC(O)Hal]- (Hal=F, Cl, Br, I)

The haloacyltris(trifluoromethyl)borate anions [(CF3)3BC(O)Hal]- (Hal=F, Cl, Br, I) have been synthesized by reacting (CF3)3BCO with either MHal (M=K, Cs; Hal=F) in SO2 or MHal (M=[nBu4N]+, [Et4N]+, [Ph4P]+; Hal=Cl, Br, I) in dichloromethane. Metathesis reactions of the fluoroacyl complex with Me3SiHal (Hal=Cl, Br, I) led to the formation of its higher homologues. The thermal stabilities of the haloacyltris(trifluoromethyl)borates decrease from the fluorine to the iodine derivative. The chemical reactivities decrease in the same order as demonstrated by a series of selected reactions. The new [(CF3)3BC(O)Hal]- (Hal=F, Cl, Br) salts are used as starting materials in the syntheses of novel compounds that contain the (CF3)3B-C fragment. All borate anions [(CF3)3BC(O)Hal]- (Hal=F, Cl, Br, I) have been characterized by multinuclear NMR spectroscopy (11B, 13C, 17O, 19F) and vibrational spectroscopy. [PPh4][(CF3)3BC(O)Br] crystallizes in the monoclinic space group P2/c (no. 13) and the bond parameters are compared with those of (CF3)3BCO and K[(CF3)3BC(O)F]. The interpretation of the spectroscopic and structural data are supported by DFT calculations [B3LYP/6-311+G(d)].     

Reaction of (carbonylimido)sulfur(IV) derivatives with TAS-fluoride, (Me2N)3S+Me3SiF2-

In the reaction of TAS-fluoride, (Me2N)3S+Me3SiF2-, with carbonyl sulfur difluoride imides RC(O)NSF2 (R = F, CF3), C-N bond, cleavage is observed, and TAS+RC(O)F2- and NSF are the final products. From TASF and RC(O)NS(CF3)F, the salts TAS+RC(O)NS(CF3)F2- (R = F (14), CF3 (15)), with psi-pentacoordinate sulfur centers in the anions, are formed. An X-ray structure investigation of 14 shows that the fluorine atoms occupy axial positions and CF3, NC(O)F, and the sulfur lone pair occupy equatorial positions of the trigonal bipyramid. The -C(O)F group lies in the equatorial plane with the CO bond synperiplanar to the SN bond. According to B3LYP calculations, this structure corresponds to a global minimum and the expected axial orientation of the -C(O)F group represents a transition state. Calculations for the unstable FC(O)NSF3- anion show a different geometry. The -C(O)F group deviates 40 degrees from axial orientation, and the equatorially bonded fluorine is, in contrast to the -CF3 group in 14, syn positioned.     

Crystal structures and solution behavior of paramagnetic divalent transition metal complexes (Fe, Co) of the sterically encumbered tridentate macrocycles 1,4,7-R3-1,4,7-triazacyclononane: coordination numbers 5 (R = i-Pr) and 6 (R = i-Bu)

The coordination chemistry of the sterically hindered macrocyclic triamines, 1,4,7-R3-1,4,7-triazacyclononane (R = i-Pr, i-Pr3tacn, and R = i-Bu, i-Bu3tacn) with divalent transition metals has been investigated. These ligands form a series of stable novel complexes with the triflate salts MII(CF3SO3)2 (M = Fe, Co, or Zn) under anaerobic conditions. The complexes Fe(i-Pr3tacn)(CF3SO3)2 (2), [Co(i-Pr3tacn)(SO3CF3)(H2O)](CF3SO3) (3), [Co(i-Pr3tacn)(CH3CN)2](BPh4)2 (4), Zn(i-Pr3tacn)(CF3SO3)2 (5), [Fe(i-Bu3tacn)(CH3CN)2(CF3SO3)](CF3SO3) (6), Fe(i-Bu3tacn)-(H2O)(CF3SO3)2 (7), and Co(i-Bu3tacn)(CF3SO3)2 (8) have been isolated. The behavior of these paramagnetic complexes in solution is explored by their 1H NMR spectra. The solid-state structures of four complexes have been determined by X-ray single-crystal crystallography. Crystallographic parameters are as follows. 2: C17H33F6FeN3O6S2, monoclinic, P2(1)/n, a = 10.895(1) A, b = 14.669(1) A, c = 16.617(1) A, beta = 101.37(1) degrees, Z = 4. 3: C17H35CoF6N3O7S2, monoclinic, P2(1)/c, a = 8.669(2) A, b = 25.538(3) A, c = 12.4349(12) A, beta = 103.132(13) degrees, Z = 4. 6: C24H45F6FeN5O6S2, monoclinic, P2(1)/c, a = 12.953(6) A, b = 16.780(6) A, c = 15.790(5) A, beta = 96.32(2) degrees, Z = 4. 7: C20H41F6FeN3O7S2, monoclinic, C2/c, a = 22.990(2) A, b = 15.768(2) A, c = 17.564(2) A, beta = 107.65(1) degrees, Z = 8. The ligand i-Pr3tacn leads to complexes in which the metal ions are five-coordinate, while it's isobutyl homologue affords six-coordinate complexes. This difference in the stereochemistries around the metal center is attributed to steric interactions involving the bulky alkyl appendages of the macrocycles.     

Bis(trifluoroacetyl) peroxide, CF(3)C(O)OOC(O)CF(3)

Pure, highly explosive CF(3)C(O)OOC(O)CF(3) is prepared for the first time by low-temperature reaction between CF(3)C(O)Cl and Na(2)O(2). At room temperature CF(3)C(O)OOC(O)CF(3) is stable for days in the liquid or gaseous state. The melting point is -37.5 degrees C, and the boiling point is extrapolated to 44 degrees C from the vapor pressure curve log p = -1875/T + 8.92 (p/mbar, T/K). Above room temperature the first-order unimolecular decay into C(2)F(6) + CO(2) occurs with an activation energy of 129 kJ mol(-1). CF(3)C(O)OOC(O)CF(3) is a clean source for CF(3) radicals as demonstrated by matrix-isolation experiments. The pure compound is characterized by NMR, vibrational, and UV spectroscopy. The geometric structure is determined by gas electron diffraction and quantum chemical calculations (HF, B3PW91, B3LYP, and MP2 with 6-31G basis sets). The molecule possesses syn-syn conformation (both C=O bonds synperiplanar to the O-O bond) with O-O = 1.426(10) A and dihedral angle phi(C-O-O-C) = 86.5(32) degrees. The density functional calculations reproduce the experimental structure very well.     

Preparation and properties of trifluorothioacetic acid-S-(trifluoromethyl)ester, CF3C(O)SCF3

Trifluorothioacetic acid-S-(trifluoromethyl)ester, CF3C(O)SCF3, was prepared by reacting CF3C(O)Cl and AgSCF3 at 50 degrees C. The compound was characterized by (13)C-, (19)F-NMR, UV, and vibrational spectroscopy as well as by gas electron diffraction (GED) and quantum chemical calculations (HF, MP2, and B3LYP methods 6-31G(d) and 6-311+G(2df) basis sets). GED and vibrational spectroscopy result in the presence of a single conformer with C1 symmetry and synperiplanar orientation of the S-CF3 bond relative to the CO bond. This result is in agreement with quantum chemical calculations which predict the anti conformer to be higher in energy by about 4 kcal/mol. An assignment of the IR (gas) and Raman (liquid) spectra is proposed, and the GED analysis results in the following skeletal geometric parameters (r(a) and angle(a) values with 3sigma uncertainties; these parameters are thermal averages and are not inconsistent with calculated equilibrium values): C=O = 1.202(6) A, C-C = 1.525(10) A, S-C(sp(2)) = 1.774(3) A, S-C(sp(3)) = 1.824 (3) A. O=C-C = 118.7(21) degrees, O=C-S = 127.1(15) degrees, C-S-C = 99.8 (13) degrees.     

((Fluoroformyl)imido)sulfuryl difluoride, FC(O)N=S(O)F2: structural, conformational, and configurational properties in the gaseous and condensed phases

Structural, conformational, and configurational properties of the gaseous molecule ((fluoroformyl)imido)sulfuryl difluoride, FC(O)N=S(O)F(2), have been studied by vibrational spectroscopy (IR (gas) and Raman (liquid)) and quantum chemical calculations (HF, MP2, and B3LYP with 6-31+G* and 6-311+G* basis sets); in addition, the solid-state structure has been determined by X-ray crystallography. FC(O)N=S(O)F(2) exists in the gas phase as a mixture of a favored antiperiplanar-synperiplanar form (the S=O double bond antiperiplanar with respect to the C-N single bond, and the C=O group synperiplanar with respect to the S=N double bond) in equilibrium with less abundant antiperiplanar-antiperiplanar, synclinal-synperiplanar, and synclinal-antiperiplanar structures. The crystalline solid at 163 K (monoclinic, P2(1)/c, a = 5.1323(7) A, b = 15.942(2) A, c = 16.798(2) A, beta = 95.974(3) degrees , Z = 12) consists of three similar antiperiplanar-synperiplanar forms.     

Perfluoromethyl fluorocarbonyl peroxide,CF3OOC(O)F: structure,conformations, and vibrational spectra studied by experimental and theoretical methods

The conformational properties and the geometric structure of perfluoromethyl fluorocarbonyl peroxide, CF(3)OOC(O)F, have been studied by matrix IR spectroscopy, gas electron diffraction, and quantum chemical calculations (HF, B3LYP, and MP2 methods with 6-311G* basis sets). Matrix IR spectra imply a mixture of syn and anti conformers (orientation of the C=O bond relative to the O-O bond) with DeltaH degrees = H(anti) degrees - H(syn) degrees = 2.16(22) kcal/mol. At room temperature, the contribution of the anti rotamer is about 3.0%. The O-O bond (1.422(15) A) is within the experimental uncertainties equal to those in related symmetrically substituted peroxides CF(3)OOCF(3) and FC(O)OOC(O)F (1.419(20) and 1.419(9) A, respectively), and the dihedral angle delta(COOC) (111(5) degrees ) is intermediate between the values in these two compounds (123(4) degrees and 83.5(14) degrees, respectively).     

Chlorocarbonyl trifluoromethanesulfonate, ClC(O)OSO2CF3: structure and conformational properties in the gaseous and condensed phases

Pure chlorocarbonyl trifluoromethanesulfonate, ClC(O)OSO(2)CF(3), has been prepared in about 58% yield by the ambient-temperature reaction between ClC(O)SCl and AgCF(3)SO(3). The conformational properties of the gaseous molecule have been studied by vibrational spectroscopy [IR(gas), IR(matrix), and Raman(liquid)] and quantum chemical calculations (HF and B3LYP with 6-31+G* basis sets); in addition, the solid-state structure has been determined by X-ray crystallography. ClC(O)OSO(2)CF(3) exists in the gas phase as a mixture of trans [ClC(O) group trans with respect to the CF(3) group] and gauche conformers, with the trans form being the more abundant [66(8)% from IR(matrix) measurements]. In both conformers, the C=O bond of the ClC(O) group is oriented synperiplanar with respect to the S-O single bond. The experimental free energy difference between the two forms, DeltaG degrees = 0.8(2) kcal mol(-1) (IR), is slightly smaller than the calculated value (1.0-1.5 kcal mol(-1)). The crystalline solid at 150 K [monoclinic, P2(1)/n, a = 7.3951(9) angstroms, b = 24.897(3) angstroms, c = 7.4812(9) angstroms, beta = 99.448(2) degrees, Z = 8] consists surprisingly of both trans and gauche forms. Whereas the more stable conformer for the more or less discrete molecules and the polarization effects would tend to favor the trans form, the packing effects would stabilize the gauche rotamer in the solid state.     

Chemistry of Bis(aryloxo)palladium(II) Complexes with N-Donor Ligands: Structural Features of the Palladium-to-Oxygen Bond and Formation of O-H.O Bonds

Reaction of palladium acetate with 2 equiv of sodium phenoxide in the presence of a chelate diamine ligand affords the complexes [Pd(OPh)(2)(N approximately N)] (N approximately N = bpy (1), tmeda (2), teeda (3), dpe (4), dmap (5)). These yellow to orange bis(phenoxo)palladium(II) complexes are thermally stable at room temperature in the solid state as well as in solution. Addition of an excess of pentafluorophenol to 1, 2, 4, and 5 affords crystalline complexes [Pd(OC(6)F(5))(2)(N approximately N)] (N approximately N = bpy (6), tmeda (7), dpe (8), dmap (9)). Crystals of 1 and 6 have been subjected to X-ray diffraction studies. Crystals of 1 are orthorhombic, space group P2(1)2(1)2(1) (no. 19), with a = 6.7655(6) ?, b = 16.0585(10) ?, c = 16.7275(13) ?, and Z = 4. Crystals of 6 are triclinic, space group P&onemacr; (no. 2), with a = 7.567(4) ?, b = 12.708(3) ?, c = 12.912(5) ?, alpha = 61.51(3) degrees, beta = 74.74(4) degrees, gamma = 88.78(4) degrees, and Z = 2. The molecular structures of 1 and 6 show them to be square-planar complexes, and the main structural difference between these complexes is the orientation of the aromatic rings. In 6 the OC(6)F(5) ligands are almost parallel in a face-to-face orientation (pi-pi stacking interactions), whereas in 1 the OC(6)H(5) units are skewed away from each other. An unexpected "mixed" alkoxo(aryloxo) complex [Pd(OCH(CF(3))(2))(OPh)(bpy)].HOPh (10) is formed when 1 is reacted with 1,1,1,3,3,3-hexafluoro-2-propanol. The molecular structure of 10 shows O-H.O hydrogen bonding (O.O = 2.642(8) ?) between the hydroxyl hydrogen of phenol and the oxygen atom of the phenoxide ligand as well as an additional C-H.O contact (C.O) = 2.95(1) ?), which can be regarded as the initial stage of a base-assisted beta-hydrogen elimination. Crystals of 10 are monoclinic, space group P2(1)/c, with a = 8.3241(14) ?, b = 11.0316(17) ?, c = 26.376(3) ?, alpha = 93.01(1) degrees, Z = 4. Spectroscopic data of complexes 1-10 indicate that the oxygen atom of the aryloxide or alkoxide ligand is extremely electron-rich, leading to high polarization of the palladium-to-oxygen bond. The bis(phenoxide) complexes 1, 2, and 4 associate with two molecules of phenol through O-H.O hydrogen bonds to form adducts [Pd(OPh)(2)(N approximately N)].2HOPh (N approximately N = bpy (11), tmeda (12), dpe (13)). The palladium complexes 6-9 with OC(6)F(5) groups show no tendency to form adducts with alcohols.     

Polyfluorinated Tris(pyrazolyl)borates. Syntheses and Spectroscopic and Structural Characterization of Group 1 and Group 11 Metal Complexes of [HB(3,5-(CF(3))(2)Pz)(3)](-) and [HB(3-(CF(3))Pz)(3)](-)

The fluorinated tris(pyrazolyl)borate ligands [HB(3,5-(CF(3))(2)Pz)(3)](-) and [HB(3-(CF(3))Pz)(3)](-) (where Pz = pyrazolyl) have been synthesized as their sodium salts from the corresponding pyrazoles and NaBH(4) in high yield. These sodium complexes and the related [HB(3,5-(CF(3))(2)Pz)(3)]K(DMAC) were used as ligand transfer agents in the preparation of the copper and silver complexes [HB(3,5-(CF(3))(2)Pz)(3)]Cu(DMAC), [HB(3,5-(CF(3))(2)Pz)(3)]CuPPh(3), [HB(3,5-(CF(3))(2)Pz)(3)]AgPPh(3), and [HB(3-(CF(3))Pz)(3)]AgPPh(3). Metal complexes of the fluorinated [HB(3,5-(CF(3))(2)Pz)(3)](-) ligand have highly electrophilic metal sites relative to their hydrocarbon analogs. This is evident from the formation of stable adducts with neutral oxygen donors such as H(2)O, dimethylacetamide, or thf. Furthermore, the metal compounds derived from fluorinated ligands show fairly long-range coupling between fluorines of the trifluoromethyl groups and the hydrogen, silver, or phosphorus. The solid state structures show that the fluorines are in close proximity to these nuclei, thus suggesting a possible through-space coupling mechanism. Crystal structures of the sodium adducts exhibit significant metal-fluorine interactions. The treatment of [HB(3,5-(CF(3))(2)Pz)(3)]Na(H(2)O) with Et(4)NBr led to [Et(4)N][HB(3,5-(CF(3))(2)Pz)(3)], which contains a well-separated [Et(4)N](+) cation and the [HB(3,5-(CF(3))(2)Pz)(3)](-) anion in the solid state. Crystal data with Mo Kalpha (lambda = 0.710 73 ?) at 193 K: [HB(3,5-(CF(3))(2)Pz)(3)]Na(H(2)O), C(15)H(6)BF(18)N(6)NaO, a = 7.992(2) ?, b = 15.049(2) ?, c = 9.934(2) ?, beta = 101.16(2) degrees, monoclinic, P2(1)/m, Z = 2; [{HB(3-(CF(3))Pz)(3)}Na(thf)](2), C(32)H(30)B(2)F(18)N(12)Na(2)O(2), a = 9.063(3) ?, b = 10.183(2) ?, c = 12.129(2) ?, alpha = 94.61(1) degrees, beta = 101.16(2) degrees, gamma = 95.66(2) degrees, triclinic, &Pmacr;1, Z = 1; [HB(3,5-(CF(3))(2)Pz)(3)]Cu(DMAC), C(19)H(13)BCuF(18)N(7)O, a = 15.124(4) ?, b = 8.833(2) ?, c = 21.637(6) ?, beta = 105.291(14) degrees, monoclinic, P2(1)/n, Z = 4; [HB(3,5-(CF(3))(2)Pz)(3)]CuPPh(3), C(33)H(19)BCuF(18)N(6)P, a = 9.1671(8) ?, b = 14.908(2) ?, c = 26.764(3) ?, beta = 94.891(1) degrees, monoclinic, P2(1)/c, Z = 4; [HB(3,5-(CF(3))(2)Pz)(3)]AgPPh(3).0.5C(6)H(14), C(36)H(26)AgBF(18)N(6)P, a = 13.929(2) ?, b = 16.498(2) ?, c = 18.752(2) ?, beta = 111.439(6) degrees, monoclinic, P2(1)/c, Z = 4; [Et(4)N][HB(3,5-(CF(3))(2)Pz)(3)], C(23)H(24)BF(18)N(7), a = 10.155(2) ?, b = 18.580(4) ?, c = 16.875(5) ?, beta = 99.01(2) degrees, monoclinic, P2(1)/n, Z = 4.     

Trifluoroacetylsulfenyl trifluoroacetate,CF(3)C(O)-S-O-C(O)CF(3), a novel compound with a symmetrically substituted S-O bond: synthesis,spectroscopic characterization,and quantum chemical calculations

The new compound trifluoroacetylsulfenyl trifluoroacetate, CF(3)C(O)SOC(O)CF(3), which possesses two identical carbonyl substituents attached to the S-O bond, has been synthesized. The IR and UV spectra of the gas phase as well as the (13)C NMR spectrum of the solution in CDCl(3) were recorded and assigned. Quantum chemical calculations were performed with the ab initio methods HF and MP2 and the density functional approach B3LYP. The 6-31G basis set was chosen in all calculations. The molecule possesses a skew structure, and according to all computational methods, the syn-syn structure (C=O bonds of both C(O)CF(3) groups synperiplanar to S-O bond) represents the most stable conformer. In agreement with the quantum chemical calculations, the presence of small amounts (< or =5%) of a second conformer (anti-syn) cannot be excluded on the basis of the IR spectrum. The calculated values for the torsional angle around the S-O bond (delta(C-S-O-C)) of the syn-syn form are smaller than 80 degrees (72-78 degrees). Comparison with theoretical results for the corresponding disulfide CF(3)C(O)SSC(O)CF(3) and peroxide CF(3)C(O)OOC(O)CF(3) indicates that the structural properties of sulfenyl compounds are more similar to those of disulfides than to those of peroxides.     

Ruthenium(II) ammine and hydrazine complexes with [N(Ph2PQ)2]- (Q = S, Se) ligands

Reactions of coordinatively unsaturated Ru[N(Ph2PQ)2]2(PPh3) (Q = S (1), Se (2)) with pyridine (py), SO2, and NH3 afford the corresponding 18e adducts Ru[N(Ph2PQ)2]2(PPh3)(L) (Q = S, L = NH3 (5); Q = Se, L = py (3), SO2 (4), NH3 (6)). The molecular structures of complexes 2 and 6 are determined. The geometry around Ru in 2 is pseudo square pyramidal with PPh3 occupying the apical position, while that in 6 is pseudooctahedral with PPh3 and NH3 mutually cis. The Ru-P distances in 2 and 6 are 2.2025(11) and 2.2778(11) A, respectively. The Ru-N bond length in 6 is 2.185(3) A. Treatment of 1 or 2 with substituted hydrazines L or NH2OH yields the respective adducts Ru[N(Ph2PQ)2]2(PPh3)(L) (Q = S, L = NH2NH2 (12), t-BuNHNH2 (14), l-aminopiperidine (C5H10NNH2) (15); Q = Se, L = PhCONHNH2 (7), PhNHNH2 (8), NH2OH (9), t-BuNHNH2 (10), C5H10NNH2 (11), NH2NH2 (13)), which are isolated as mixtures of their trans and cis isomers. The structures of cis-14 and cis-15 are characterized by X-ray crystallography. In both molecular structures, the ruthenium adopts a pseudooctahedral arrangement with PPh3 and hydrazine mutually cis. The Ru-N bond lengths in cis-14.CH2Cl2 and cis-15 are 2.152(3) and 2.101(3) A, respectively. The Ru-N-N bond angles in cis-14.CH2Cl2 and cis-15 are 120.5(4) and 129.0(2) degrees, respectively. Treatment of 1 with hydrazine monohydrate leads to the isolation of yellow 5 and red trans-Ru[N(Ph2PS)2]2(NH3)(H2O) (16), which are characterized by mass spectrometry, 1H NMR spectroscopy, and elemental analyses. The geometry around ruthenium in 16 is pseudooctahedral with the NH3 and H2O ligands mutually trans. The Ru-O and Ru-N bond distances are 2.118(4) and 2.142(6) A, respectively. Oxidation reactions of the above ruthenium hydrazine complexes are also studied.     

Reactions of (PCP)Ru(CO)(NHPh)(PMe3) (PCP = 2,6-(CH2PtBu2)2C6H3) with substrates that possess polar bonds

The Ru(II) amido complex (PCP)Ru(CO)(PMe(3))(NHPh) (1) (PCP = 2,6-(CH(2)P(t)Bu(2))(2)C(6)H(3)) reacts with compounds that possess polar C=N, C triple bond N, or C=O bonds (e.g., nitriles, carbodiimides, or isocyanates) to produce four-membered heterometallacycles that result from nucleophilic addition of the amido nitrogen to an unsaturated carbon of the organic substrate. Based on studies of the reaction of complex 1 with acetonitrile, the transformations are suggested to proceed by dissociation of trimethylphosphine, followed by coordination of the organic substrate and then intramolecular N-C bond formation. In the presence of ROH (R = H or Me), the fluorinated amidinate complex (PCP)Ru(CO)(N(Ph)C(C(6)F(5))NH) (6) reacts with excess pentafluorobenzonitrile to produce (PCP)Ru(CO)(F)(N(H)C(C(6)F(5))NHPh) (7). The reaction with MeOH also produces o-MeOC(6)F(4)CN (>90%) and p-MeOC(6)F(4)CN (<10%). Details of the solid-state structures of (PCP)Ru(CO)(F)(N(H)C(C(6)F(5))NHPh) (7), (PCP)Ru(CO)[PhNC{NH(hx)}N(hx)] (8), (PCP)Ru(CO){N(Ph)C(NHPh)O} (9), and (PCP)Ru(CO){OC(Ph)N(Ph)} (10) are reported.     

Syntheses and reactions of the fluorinated cyclic thionylphosphazene NSO(Ar)[NPF(2)]2(Ar = 4-t-BuC(6)H(4)-) with difunctional reagents

The S-aryl substituted thionylphosphazene (Cl(2)PN)(2)[4-t-BuC(6)H(4)(O)SN] (1) was prepared by Friedel-Craft's reaction of NSOCl(NPCl(2))(2) with tert-butylbenzene. When it reacted with excess KSO(2)F at 110 degrees C, the P-Cl bonds of 1 were fluorinated, yielding the tetrafluorothionylphosphazene, (F(2)PN)(2)[4-t-BuC(6)H(4)(O)SN] (2). An equimolar reaction of 2 with dilithiated 1,3-propanediol in THF at -78 degrees C resulted in the formation of the ansa-substituted compound CH(2)(CH(2)O)(2)[FPN](2)[4-t-BuC(6)H(4)(O)SN] (3). The crystal structures of 2 and 3 were determined. In 3 the ansa ring is trans on the PNS heterocycle with respect to the aryl group. Reaction of 2 with the disiloxane (CF(2)CH(2)OSiMe(3))(2), in the presence of catalytic amounts of CsF in THF at 90 degrees C, resulted in the formation of the dispiro compound [(CF(2)CH(2)O)(2)PN](2)[4-t-BuC(6)H(4)(O)SN] (4). Compounds 1-4 were characterized by IR, NMR ((1)H, (13)C, (19)F, (31)P), mass spectral, and elemental analyses.     

S-(fluoroformyl)O-(trifluoroacetyl) thioperoxide, FC(O)S-OC(O)CF3: gas-phase structure and conformational properties

The geometric structure and conformational properties of S-(fluoroformyl)O-(trifluoroacetyl) thioperoxide, FC(O)S-OC(O)CF3, were investigated by gas electron diffraction, matrix isolation infrared spectroscopy, and quantum chemical calculations (B3LYP with the 6-31G and aug-cc-pVTZ basis sets and MP2 with the 6-31G basis set). The experimental methods result in a mixture of two conformers with gauche conformation around the S-O bond. In the main conformer (82(7)% according to GED at 298 K), the C=O bond of the FC(O) group is oriented syn with respect to the S-O bond and phi(C-S-O-C) = 75(3) degrees . In the minor conformer (18(7)%), this C=O is oriented anti. Both conformers possess syn orientation of the C=O bond of the CF3C(O) group. The conformational properties and geometric parameters are reproduced reasonably well by the quantum chemical calculations, except for the S-O bond length, which is predicted too long by 0.04 A (B3LYP/aug-cc-pVTZ).     

Synthesis and characterization of trifluoromethyl fluoroformyl peroxycarbonate,CF3OC(O)OOC(O)F

The synthesis of CF(3)OC(O)OOC(O)F is accomplished by the photolysis of a mixture of (CF(3)CO)(2)O, FC(O)C(O)F, CO, and O(2) at -15 degrees C using a low-pressure mercury lamp. The new peroxide is obtained in pure form in low yield after repeated trap-to-trap condensation and is characterized by NMR, IR, Raman, and UV spectroscopy. Geometrical parameters were studied by ab initio methods [B3LYP/6-311+G(d)]. At room temperature, CF(3)OC(O)OOC(O)F is stable for many days in the liquid or gaseous state. The melting point is -87 degrees C, and the boiling point is extrapolated to 45 degrees C from the vapor pressure curve log p = 8.384 - 1715/T (p/mbar, T/K). A possible mechanism for the formation of CF(3)OC(O)OOC(O)F is discussed, and its properties are compared with those of related compounds.