Showing papers in "Inorganica Chimica Acta in 1981"

Abstract: The roles of transition metal complexes in catalysis are discussed in the light of recent studies on the kinetics and mechanisms of homogeneous catalytic hydrogenation reactions

Abstract: The kinetics of anation of Pd(1,1,7,7-Et 4 dien)OH 2+ 2 and Pd(1,1,4-Et 3 dien)OH 2+ 2 by chloride ion were studied under pressures up to 1 kbar using a high pressure stopped-flow system. The construction and testing of the latter system are discussed in detail. The rate and activation parameters for the above reactions are: k(25 °C) = 4.2 ± 0.1 and 1558 ± 68 M −1 sec −1 ; ΔH≠ = 13.4 ± 0.4 and 10.5 ± 0.7 kcal mol −1 ; ΔS≠ = −10.7 ± 1.2 and −8.7 ± 2.3 cal K −1 mol −1 ; and ΔV≠ = −3.0 ± 0.2 and −2.7 ± 0.2 cm 3 mol −1 , respectively. These are considered as evidence for an associative type of anation process.

Abstract: The isolation and characterization of a series of transition metal complexes is described with the ligand bpenH 2 in both neutral and deprotonated forms. The ligand acts as a planar N 4 tetradentate in the monomeric deprotonated complexes of general forms M(bpen)nH 2 O (M = Cu II , Ni II , Pd II or Pt II . Metal chloride and perchlorate salts of the neutral ligand, of general formulae M(bpenH 2 )Cl 2 nH 2 O and M 2 (bpenH 2 ) 3 (ClO 4 ) 4 nH 2 O, are reported (M = Mn II , Fe II , Co II , Ni II , Cu II or Zn 11 ) with the ligand bonding through pyridine-N and amine-O atoms in a bridging bis-bidentate function. In the chloride complexes high-spin six-coordinate geometries are indicated for the polymeric solid products. The perchlorate complexes are dimeric and high-spin, with each metal atom exhibiting N 3 O 3 six-coordination. Proton NMR studies on the ligand show coupling of the amide protons with those of the central ethylene group. Deprotonation is confirmed by loss of this coupling for the Ni 11 , Pd 11 and Pt 11 chelates, 1 H 195 Pt coupling being observed in the latter compound The neutral and deprotonated chelate forms also are readily differentiated by thier IR absorption. Deuterium isotopic substitution of amide protons has been used to assist IR assignments.

Abstract: The structure of the title compound has been determined by single crystal X-ray diffraction. The crystals are orthorhombic a = 13.435 (2), b = 18.812(3), c = 18.739(2) A, Z = 4, space group Pc21n (No 33). A total of 3291 observed reflections were measured and refined to R = 0.087. The copper is inn a distorted tetrahedral environment (P3F) with CuP = 2.325(3), 2.310(3) and 2.316(2), and CuF = 2.062(6) A. The solvent and temperature dependent solution behaviour of this complex has been examined by a combination of 1H, 19F and 31P NMR spectroscopy and conductivity measurements. The synthesis and properties of the unsolvated complex are briefly described.

Abstract: The 5, 8, 9, and 11 vertex deltahedra containing the minimum number of tetrahedral chambers are inherently fluxional since certain possible diamond-square-diamond rearrangements can lead directly to a polyhedron identical to the original one except for interchanges of some vertices. By this criterion the 6, 10, and 12 vertex deltahedra are inherently rigid. The 7 vertex pentagonal bipyramid is also inherently rigid but can stereochemically non-rigid in cases where a capped octahedron is an accessible intermediate. These topological observations are consistent with known information on the stereochemical non-rigidity and hydrolytic stability stability of the delta-hedral borane anions BnH2−n and the stereochemical non-rigidity of MLn coordination complexes. Thus the stereochemical non-rigidity of all ML7 complexes investigated as contrasted with the stereochemical rigidity of B7H2−7 can be related to the energetic accessibility of capped octahedral species in ML7 complexes but not in B7H2−7.

Abstract: Trinuclear [{(Ph{2}P){3}CH}Ag{3}(O{2}CR'){3}], dinuclear [{(Ph{2}P){2}CHR}Ag{2}(O{2}CR'){2}], [{(Ph{2}P){2}CHR}{2}Ag{2}](BF{4}){2} and (Rh{2}(Cl)(CO){2}{(Ph{2}P){2}CHMe}{2}][RhCl{2}(CO){2}], and mononuclear (Rh{(Ph{2}P){2}CHR}{2}](BF{4}), (Rh{(Ph{2}P){2}CHR}{2}HCl](BF{4}), d [Rh{(Ph{2}P){2}CHR}{2}Cl(HgCl)](BF{4}) and (Rh{(Ph{2}P){2}CHR}{2}O{2}](BF{4}) (R = H,Me) were synthesized from the phosphines tris(diphenylphosphino)methane ((Ph{2}P){3}CH), bis(diphenylphosphino)methane ((Ph{2}P){2}CH{2}) and 1,1-bis(diphenylphosphino)ethane ((Ph{2}P){2}CHMe). The }1{H, }1{}3{C and }3{}1{P NMR spectra were investigated and for the mononuclear rhodium compounds compared with their 1,2-bis(diphenylphosphino)ethane and 1,3-bis(diphenylphosphino)propane analogues. The }3{}1{P NMR spectra of the silver complexes revealed besides normal values for J(}1{}0{}7{Ag-}3{}1{P) (640 and 500 Hz for the gAgP and AgP{2} systems, respectively) a small{3}J(}1{}0{}7{Ag-{3}{1}P) of about -4 Hz and an exceptionally large }2{J(}3{}1{P-}3{}1{P) of 170 Hz. A large positive charge on the P-atoms in [{(Ph{2}P){2}CH{2}}Ag{2}(O{2}CR){2}] and [{(Ph{2}P){2}CH{2}}Ag{2}](BF{4}){2} was calculated from the chemical shifts of the methylene protons.On the basis of }3{}1{P NMR data methyl substitution in (Ph{2}P){2}CHR resulted in formation of only one of the possible isomers for [{(Ph{2}P){2}CHMe}{2}Ag{2}](BF{4}){2}, [Rh{2}(CO){2}(Cl){(Ph{2}P){2}CHMe}{2}][RhCl{2}(CO){2}] and [Rh{(Ph{2}P){2}CHMe}{2}O{2}](BF{4}), but two isomers for [Rh{(Ph{2}P){2}CHMe}{2}](BF{4}) and [Rh{(Ph{2}P){2}CHMe}HCl](BF{4}). These results are interpreted in terms of metal@?chelate ring puckering.

Abstract: A number of mixed olefin diazabutadiene (RN: CR′CR′:NR; DAB) complexes of zero-valent palladium [(olefin)Pd(DAB)] have been prepared by the simultaneous reactions of an activated olefin and a DAB with an appropriate source of Pd(O). The complexes have been characterized by 1 H- 13 C NMR, I.R. and Raman spectroscopy. The physical and chemical properties of the complexes are dependent upon the olefin and DAB ligands employed. Complexes where olefin = dimethylfumarate(dmf) or diethylfumarate (def) and DAB = tBuN:CHCH:NtBu (DAB H tBu ) readily undergo ligand displacement reactions with PPh 3 and tBuNC (leading to displacement of the DAB), oxidative addition of the olefin) yielding a dinuclear Pd(II) complex. ([(methylallyl)(chloride)Pd] 2 tBuN: CHCH:NtBu) and react with excess olefin yielding a dinuclear Pd(O) complesx ([(olefin) 2 Pd 2 ]tBuN: CHCH:NtBu).

Abstract: equilibrium constants for the complexes formed between the calcium ion and a series tetracyclines, i.e. tetracycline, oxytetracycline, doxycycline, minocycline, were protentiometrically determined at 37°C in aqueous medium NaCl 0.15 mol dm −3 . The distribution of the complexes was then simulated under physiological conditions at therapeutic levels of the drugs. Results are discussed concerning the possible effect of the calciumtetracyclines interactions regarding the mode of action and the distribution of these antibiotics in the human body.

Abstract: 31P and 195Pt NMR data for the triangular clusters [Pt3(μ2-CO)3(tertiary phosphine)3] tertiary phosphine = PCy3, PPri3, PPri2Ph, P(CH2Ph)Ph2, are reported The nuclearity of the complexes in solution is readily identified via 31PNMR using the multiplicity data in the 195Pt satellites The values 1J(195Pt, 195Pt) have been measured and fall in the range 1571–1619 Hz It is suggested that the values 2J(195Pt, 31P) and 3J(31P, 31P) can be useful indicators for the presence of platinum—platinum bonds

Abstract: The crystal structures of diquabis(p-chlorophenoxyacetato)copper(II) (1) and diaquabis(phenoxyacetato)zinc(II) (2) have been determined by X-ray methods from diffractometer data and refined by least squares to R 03059 (1) and 03032 (2) for 999 and 1472 `observed' reflections respectively. Crystals of (1) are triclinic, space group P 1 with Z = 1 in a unit cell of dimensions a = 7.065(3), b = 13.273(11), c = 5.114(2) A, α = 93.72(5), β = 103.64(4), γ = 81.63(5)°. The complex has a centrosymmetric tetragonally-distorted octahedral stereochemistry, the coordination sphere consisting of two water oxygens [CuO, 1.960(4) A] and two carbonyl oxygens [CuO, 1.956(4) A] from different bidentate phenoxyacetate ligands about the square plane while the axial positions are occupied by two ether oxygens [CuO, 2.406(4) A]. The water oxygens are tied into a two-dimensional hydrogen-bonded network involving the un-co-ordinated carboxyl oxygens (O⋯O, 2.652 A) and the co-ordinated carboxyl oxygens with the O(H2)⋯O distances of 2.164 and 2.708 A respectively. Compound (2) is monoclinic, spacegroup C2 with Z = 2 in a cell of dimensions a = 11.625(3), b = 5.221(1), c = 13.767(4) A, β = 101.05(5)°. The complex (2) possesses a distorted trapezoidal pyramidal stereochemistry involving two water oxygens [ZnO, 1.994(1) A] and four carboxyl oxygens from phenoxyacetate ligands [ZnO, 2.118(1) A]. In both structures the phenoxy ligands are essentially planar and have similar distances and angles to those found in the structure fo un-co-rdinated phenoxyacetic acid. Single-crystal and powder diffractionaer X-ray data are also reported for diaquabis(p-chlorphenoxyacetato)zinc(II) (3), which is isostructural with (2).

Abstract: Bis(1-methylthyminato-N3) cis -diammineplatinum(II), cis -Pt(NH 3 ) 2 (C 6 H 7 N 2 O 2 ) 2 , is readily protonated to give a compound of composition cis -[Pt(NH 3 ) 2 (C 6 H 7 N 2 O 2 )(C 6 H 8 N 2 O 2 )] + X − (X = Cl − , NO − 3 , ClO − 4 ). The pK value for the protonation is 2.05 ± 0.05. The compound contains an anionic 1-methylthymine ligand and neutral 1-methylthymine ligand in an unusual iminol tautomer structure, both being coordinated to Pt(II) through N(3). The neutral thymine ligand is only weakly bound to Pt(II) and readily displaced. Spectroscopic data ( 1 H-NMR, UV, IR) are presented. A model for a possible nucleobase mispairing mechanism catalyzed through metal coordination at N(3) of thymindine, is proposed.

Abstract: [Cu(C5H4N4)(H2O)4]SO4·2H2O, orthorhombic, space group Pbca, a = 11.912(5) A, b = 17.828(2) A, c = 12.673(2) A, Z = 8. The data were collected on a CAD-4 diffractometer using an on-line PDP 11/55 computer for structure analysis. The structure was refined to R = 0.119. The Cu ion is octahedrally surrounded, binding equatorially to N(7) and N(9) in two symmetry related purine rings, thus producing a polymeric chain. The other positions are occupied by water molecules. The CuN(9) distance (2.036 A) is in the range expected for a dative bond while the CuN(7) distance (1.903 A) is close to the value expected for a covalent bond. The purine ligand is neutral being protonated at N(1). The sulphate group is disordered and there is a large degree of pseudo-symmetry in the structure.

Abstract: A detailed study is reported of the ability of a range of metallophthalocyanines to photoreduce methylviologen, in the presence of triethanolamine. Certain species are demonstrated to be effective photocatalysts, using light of wavelength corresponding to the Q band in their electronic spectrum. However quantum yields are very low. Other metallophthalocyanines are shown to be inactive under similar conditions. Using electrochemical and spectroscopic data the energies of the photoactive states are estimated. From these results the thermodynamic driving forces for both oxidative and reductive quenching are calculated, together with the thermal following and back reactions. By comparison with other photoactive systems, with known kinetic data, it is demonstrated that the thermodynamic data are a useful guide to photoactivity when kinetic data are unavailable.

Abstract: Appropriate combinations of 1H, 13C and 113Cd NMR have been used to study ca. 0.05 M solutions of a wide range of 113Cd-enriched thiolatocadmates formed from the corresponding poorly soluble cadmium thiolates in the presence of excess thiolate. In addition, MCD spectra have been recorded for dilute, ca. 10−5M, solutions of a representative set of thiolate complexes of cadmium. Cadmium-113 chemical shifts are given for the complexes formed by 31 different thiolates individually in water at ambient probe temperature, and slow-exchange 1H and/or 13C and/or 113Cd NMR spectra are reported for several typical complexes at reduced temperature in CD3OD. In aqueous solution at ambient probe temperature, ligands with vicinal thiolate groups and −SCH2CHRS− (R = H, Me, Et, CH2OH, CH2SO−3 or CH2S−)) form bis(chelate) complexes which have δCd ⪖ 778 ppm, less shielded than the range for tetrahedral cd(SR)2−4 (R = Me, Et, Pr, Me2CH, Bu, EtMeHC, Ph, PhCH2, CH2CH2X (X = OH, NH2, or CO−2, CH2CH(OH)Me, CH2CH(OH)CH2OH, LCH2CH(NH2)CO−2, or CH2CO−2 for which δCd < 666 ppm. Increasing alkyl substitution kin the α-position causes increasing shielding of the cadmium resonance for both the chelate complexes and the complexes of monodentate thiolates. Separate 113Cd and, in some cases, 1H resonances have been found for members of the series [Cd(SR)n(SR′)4−n]2− (R = Me, R′ = CHMe2; R = Ph, R′ = CH2Ph; n = 0−4) and [Cd(S(CH22S)n/2(SCHMe2)4−n2− (n = 0,2, or 4) at low temperature: 113Cd chemical shifts change additively or near-additively in these series. The MCD data indicate that in most of the complexes formed at the ca. 10−5M concentrations used for the optical studies, the local microsymmetry about the cadmium approaches tetrahedral. Specifically, the complexes [Cd(SR)2.5]0.5n−n (R = Me, Et, or Pr) exhibited well-resolved, symmetric A terms under the S → Cd charge transfer band in the 250 nm region. Complexes of the dithiolates −S(CH2nS− (n = 2,3, or 4) and −SCH2CHMeS− gave MCD spectra which were much broader and less well-resolved. The spectra of the systems containing the vicinal dithiolates showed the formation of two complexes, as the band centre of the MCD signal blue-shifted when L/M was increased from 1 to 2; at L/M = 2, bis(dithiolate) complexes are most likely formed. With the ligand −SCH2CHCH2OH (BAL), the corresponding S− spectra were similar at L/M = 2 but quite different at L/M = 1. A B term centred on the 250 nm charge transfer band was observed for the solution where BAL/Cd = 1, demonstrating loss of tetrahedral symmetry about cadmium, probably due to ligation by the ligand hydroxyl group. These studies provide 113Cd NMR and MCD ‘fingerprint’ data necessary for the interpretation of the corresponding spectra of related and more complicated, biologically important cadmium complexes.

Abstract: The crystal structure of 8-hydroxyquinolinatocarbonyltriphenylphosphine, C 28 H 21 O 2 NPRh, was determined from 2995 unique observed reflections obtained with a computer automated diffractometer. The unit cell is triclinic with a = 14.154 A , b = 9.984 A , c = 9.409 A , α = 116.16°, β = 90.09°, γ = 99.60°, Z = 2 with space group P 1 . Refinement of the data with anisotropic thermal parameters converged to R = 4.9%. The compound was prepared by the reaction between [Rh(oxine)(Co) 2 ] and triphenylphosphine. The structure determination shows that the carbonyl group trans to the nitrogen atom of the 8-hydroxyquinolinato ligand was substituted by the triphenylphosphine ligand, which indicate that the nitrogen atom of the chelate ring has a larger trans influence than the oxygen atom.

Abstract: The synthesis is described of some bis-picollinamide ligands in which N 4 tetradentate function on coordination would enfore severe intramolecular steric interactions. These ligands are N,N′-bis(6′-methylpyridine-2′-carboxamide)-1-ethane (6-mebpenH 2 ), N,N′-bis(6′-mehtylpyridine-2′-carboxamide)-1,2-benzene (6-mebpbH 2 ) and N,N′N-bis(2′-quinolylcarboxamine)-1,2-ethane (bqenH 2 ). Their complexing abilities with bivalent Cu, Ni and Pd have been studies, and comparison are made with analogous unhindered ligands reported previously. The complexes isolated each have characterized by microanalysis, magnetic susceptibility, thermogravimetrinc analysis, and by visible, i.r. and n.m.r. spectral data. In the compound Pd(6-mebpenH 2 )Cl 2 the ligand displays an apparent unique trans -bidentate function. The deprotonated complexes isolated with the three ligands have N 4 tetradentate coordination, with resultant steric strain. Deuterium isotopic substitution has been used to assist with i.r. assignments.

Abstract: Electrochemical oxidation of cobalt sandwich complexes CoCpL, where Cp is η5-cyclopentadienyl and L an η4-diolefine or cyclobutadiene ligand, was investigated by means of cyclic voltammetry and polarography. Oxidation is reversible or nearly so for compounds where L is a cyclic diolefine (I–III) or a cyclobutadiene (VI) and for the methylated complexesCo(C5Me5)(C5Me5R) (R = Me, Ph) (VII) and irreversible for CoCp(C5H5Ph) (IV) and the complexes V where L is a divinylborane.

Abstract: Discovery of the compounds [Pt(C 2 H 4 ) 3 ] and [Pt(C 2 H 4 ) 2 (PR 3 )], and new procedures for preparing [Pt(C 2 H 4 )(PR 3 ) 2 ] and [Pt(cod) 2 ], have enabled these species to be used in the synthesis of many new organoplatinum compounds containing metal-metal bonds. This article summarises recent progress in this field.

Abstract: The iron(III) compounds of N,N′-ethylene-bis (o-hydroxyphenylglycine), Mn+[Fe(ehpg)]−JxH2O have been isolated and two district isomorphous series characterised; one (labelled α) for Li+, Na+, K+, Ca2+, Ba2+, the other (labelled β) for Mg2+ and Na+ only. A full X-ray structural analysis of each type is reported. Crystals of Na[Fe(ehpg)] ·4H2O (α) are orthorhombic a = 37.66(2), b = 7.12(1), c = 24.44(1) A, space group Pbcn (D142h, no. 60), and those of Mg[Fe(ehpg)]2·9H2O (β) are monoclinic a = 17.074(15), b = 13.099(11), c = 20.868(11) A, β = 113.57(5)°, space group I2/c (non-standard setting C62h, no. 15). Data for each analysis were collected by diffractometer, the structures solved for 2191 and 3124 reflections, respectively, by coventional Patterson and Fourier techniques and were refined by block-diagonal least-squares to final R-values of 0.067 and 0.038, respectively. The asymmetric unit of the sodium salt contains one [Fe(meso-ehpg)]− ion with cis phenoxy and carboxylate oxygens in a general position and one-half [Fe(rac-ehpg)]− ion, with trans carboxylate oxygens, on a C2 axis. In each case, the co-ordination polyhedron is distorted octahedral [mean FeN 2.149(2), FeO (phenolic) 1.906(15), FeO (carboxylate) 2.042(40) A, NFeN′ 79.9 (1.0), NFeO (phenolic) 88.1(1.3), N-FeO (carboxylate) 77.9(0.2)°]. The crystal lattice contains hydrophilic channels, with disordered water molecules and Na+ ions, and hydrophobic regions bounded by phenyl groups. The magnesium salt contains only the [Fe(rac-ehpg)]− ion in general positions, with the same configuration as the sodium salt [mean FeN 2.166(13), FeO (phenolic) 1.911(10), FeO (carboxylate) 2.042(7) A, NFeO (phenolic) 88.4(8) and NFeO (carboxylate) 77.2(5)°.

Abstract: Neutral and anionic pentachloro- or pentafluorophenyl palladium(II) complexes containing biimidazolate, bibenziimidazolate or 4,5-4′,5′-tetramethylbiimidazolate anions, which act as tetradentate bridging ligands, have been prepared by reacting mononuclear palladium acetylacetonate complexes with 2,2′-biimidazol, 2,2′-bibenziimidazol or, respectively 4,5-4′,5′-tetramethylbiimidazol, or by treating the thallium salts of these ligands with binuclear halide-bridged palladium(II) derivatives The structure of the resulting complexes has been elucidated by conductance studies and IR spectroscopy

Abstract: Complexes, [LnL1(H2O)2] (ClO4)3·4H2O, where L1 is 2,5,11,14-tetramethyl-3,4,12,13,19,20-hexaazatricyclol[13.3.1.1.6,10] eicosa-1(19),2,4,6,8,10(20),11,13,15,17-decaene and Ln is Tb, Dy, Ho, Er, Tm, Yb or Lu, have been prepared by the condensation of 2,6-diacetylpyridine with hydrazine in the presence of metal-ion templates and characterized by spectral data, thermal and elemental analysis. They are proposed to have six-coordinate and octahedral geometry with four nitrogen donor atoms occupying the equatorial plane and two water molecules in the axial positions. In contrast, analogous reactions involving the lighter lanthanides yield ring-opened complexes [LnL22] (ClO4)3·2H2O, where L2 is (6-acetyl-pyrid-2-yl)methyl ketone azine, Ln is La, Pr, Nd or Sm and [LnL2(H2O)2] (ClO4)3·2H2O, where Ln is Eu or Gd. In addition to the above major products small amounts of lanthanide complexes of 2,6-diacetylpyridine (L3) have been isolated from the reaction and identified by spectral, thermal, and elemental analysis. These complexes are formulated as [LnL34](ClO4)3·2H2O, where Ln is La, Pr, Nd or Sm, [LnL33(H2O)](ClO4)3·2H2O, where Ln is Eu or Gd, and [LnL33](ClO4)3·3H2O, where Ln is Tb, Dy, Ho, Er, Tm, Yb or Lu. Treatment of [LnL1(H2O)2](ClO4)3·4H2O with water yields complexes of the ring-opened ligand L2 of general formula [LnL2(H2O)2](ClO4)3·2H2O, where Ln is Tb, Dy, Ho, Er, Tm, Yb or Lu.

Abstract: A series of ten bis(dithiolato)oxotechnetate(V) complexes has been prepared using ligand exchange reaction. Starting from Tc(V) gluconate in aqueous or aqueous/ethanolic solution, complexes with saturated, olefinic and aromatic dithioles have been obtained. Mass, infrared, n.m.r., and UV-visible data of the resulting compounds are reported.

Abstract: The ESR, magnetic susceptibilities, IR and electronic spectra, and electric conductivities of solid state were measured for a series of nickel complexes of the general formula Ni(diamine) 2 ClX 2 which appeared to contain ‘tervalent nickel’ in order to elucidate to oxidation state of the nickel. Based on these data they were characterized and classified into the following three groups. A) Ni(en) 2 Cl 3 and Ni(tn) 2 Cl 3 , low-spin d 7 Ni(III) complexes; B) Ni(pn) 2 Cl 3 , Ni(cyn) 2 Cl 3 , Ni(btn) 2 Cl 3 and Ni(en) 2 Cl(ClO 4 ) 2 , Ni(II)Ni(IV) mixed valence complexes; and C) Ni(phn) 2 Cl 3 , probably Ni(II) complex with cation radical ligand.

Abstract: Complexes of imidazoline-2(1,3H)-thione (ImT,L), have been prepared with Co(II) and Zn(II) salts. Stoichiometries of the complexes, ML2X2, for the halides and ML4X2 for the nitrates and perchlorates, have been established by chemical analysis. Thermal analysis has revealed the extent of hydration among the cobalt complexes. The solid complexes have been further characterised by means of magnetic susceptibility data, infrared and visible spectral measurements. The soluble complexes have been studied by means of electrolytic conductance measurements and their visible spectra have also been recorded. Ligand field parameters have been determined and probable structures assigned. The ligand coordinated by means of its exocyclic sulphur atom and one of its ring nitrogen atoms in the solid complexes. For the soluble complexes coordination involves the sulphur atom only.

Abstract: The synthesis of the title compound and of its adducts with O 2 , CO, CO 2 , SO 2 , tertiary phosphines is described. The reactions of the dioxygen adduct with sulfur dioxide and carbon monoxide are also reported.