Microwave spectrum of dichloroborane (BHCl2)

The microwave spectrum of dichloroborane has been observed and the rotational constants of four isotopic species are determined as follows: A = 46911.09(7), B = 3185.937(10) and C = 2980.425(14) MHz for the normal species, A = 46747.14(8), B = 3099.543(14) and C = 2904.037(14)MHz for BHCl³⁷Cl, A = 49302.05(24), B = 3185.536(32) and C = 2989.368(51) MHz for ¹⁰BHCl₂ and A = 35153.18(9), B = 3186.026(15) and C = 2918.233(11) MHz for BDCl₂. The following complete r_s structure was determined: r_s(BH) = 1.184(2) Å, r_s(BCl) = 1.735(2) Å and ∠ ClBCl = 120.4(2)°. The hyperfine structure due to the two chlorine and one boron nuclei has been analysed.     

Étude en ondes millimétriques des variétés isotopiques en 13c et 18o de la molécule de trioxane: Structure de la molécule

The rotational spectra of the molecules (¹³CH₂O)(¹²CH₂O)₂ and (CH₂¹⁸O) (CH₂¹⁶O)₂ have been investigated in the region 30–290 GHz. The rotational constants determined are (MHz):A = 5271.106±0.007, B = 5176.405 ±0.007, C = 2904.376±0.34 for the former, andA = 5267.34±0.3, B = 508I.106±0.3, C = 2872.378± 10 for the latter molecule.The parameter C of the parent molecule (CH₂O)₃ has been determined: 2933.95 ±0.34 MHz. With the value A = B = 5273.258 ±0.002 for the parent molecule the following structural parameters were determined: r(C-O) = 1.4205± 0.005 Å, ∠COC = 109.5±0.5°, ∠OCO = 112±0.5°.     

Stereochemically active lone pairs of electrons in subvalent main fourth-group compounds. The crystal and molecular structures of {η5-C5H5Co[P(OC2H5)2O]3}2MII (M = Sn,Pb)

The air-stable, mixed main group-transition metal, trinuclear sandwich oxygen tripod 2/1 complexes, {η⁵-C₅H₅Co[P(OC₂H₅)₂O]₃}₂M, (1, M = Sn): C₃₄H₇₀Co₂O₁₈P₆Sn, a 18.871(12), b 22.461(12), c 12.671(7) Å, β 92.53(5)°, monoclinic space group P2₁/a, d_calc 1.472 g cm⁻³, Z = 4, R = 9.5%: 2 (M = Pb): C₃₄H₇₀Co₂O₁₈P₆Pb, a 18.787(8), b 22.397(9), c 12.674(3) Å, β 92,01(3)°, monoclinic space group P2₁/a, d_calc 1.594 gcm⁻³, Z = 4, R = 7.2%, have been subjected to single crystal X-ray analysis. Both complexes show a stereochemically active lone pair at the metal and coordination to two tridentate η⁵-C₅H₅Co[P(OC₂H₅)₂O]₃ groups. The angles through the MO₆ units are CoMCo 149.04(14)° and 150.96(7)° for M = Sn and Pb, respectively. The tilting of the two tripod ligand moieties is reflected in the MO internuclear distances which range from 2.24(3) to 2.83 (3) Å for M-Sn and 2.40 (2) to 2.66(3) Å for M = Pb, differences of 0.59(3) and 0.26(3) Å, respectively. The average distances are 2.48(3) and 2.51(2) Å for 1 and 2 which are isostructural.     

The structure of the dithionite ion

The Raman spectra of aqueous and solid sodium dithionite have been recorded. Differences in the location, intensity, and number of observed bands are attributed to conformational changes in the dithionite ion. The structure of the aqueous ion is non-planar with a C_2h symmetry with an SS bond distance estimated to be 0.220–0.226 nm, as opposed to the dithionite structure in the Na₂S₂O₄·2H₂O salt which is known to have C_2ν structure with a bond distance of 0.2389 nm. The Raman spectra of aqueous dithionite are assigned to A_g (SO) = 997 cm^?1; B_g (SO) at 912 cm^?1, B_g SO₂ twist at 324 cm^?1. The remaining bands are a strong A_g, the SO₂ wag, the SO₂ scissor, and the SS stretch at 584, 461, and 232 cm^?1, respectively, but due to coupling all three motions are expected to exhibit substantial SS character. The variation of the spectra of the solid and aqueous sodium dithionite indicate strong environmental effect on the structure of the anion.     

Magnetic interactions in ternary cobalt oxides with cubic perovskite structure

Magnetic properties were measured on the cubic perovskite systems SrCoO_3?δ, (La_1?xSr_x)CoO₃ (0.5 ≦ x ≦ 1.0), and Sr(Co_1?xMn_x)O₃ (0 ≦ x ≦ 1.0). It is found that S²⁺ and La³⁺ ions strongly affect the spin state of the Co²⁺ ion and that the Mn⁴⁺ ion located at the octahedral site affects the spin state of Co⁴⁺ ion. The magnetic properties (T_c, T_θ, and σ) are explained by the magnetic interaction Co³⁺OCo³⁺, Co³⁺OCo⁴⁺, Co⁴⁺OCo⁴⁺, Mn⁴⁺OMn⁴⁺, and Mn⁴⁺OCo⁴⁺ in these systems.     

Microwave spectrum of cyclohexanecarbonitrile

The microwave rotational spectrum of cyclohexanecarbonitrile was investigated in the frequency region 8–40 GHz. From the measured transition frequencies the rotational constants of the two molecular were derived (equatorial isomer: A = 4238.77, B = 1399.172, C = 1128.845 MHz; axial isomer: A = 3005.58, B = 1763.483, C = 1558.615 MHz). Assuming the values of 1.531, 1.096 and 1.159 Å, respectively, for the CC, CH and CN distances, and supposing that the ring structure has the same symmetry as in cyclohexane, the following structural parameters were also obtained: equatorial isomer CCC (carbon ring) = 111.40°, r(CCN) = 1.489 Å, HCCN = 107.42°; axial isomer CCC (carbon ring) = 111.65°, r(CCN) = 1.489 Å, HCCN = 105.53°.     

Estimates for systematic empirical corrections of consistent 4–21G ab initio geometries and their correlations to total energy group increments

The structural parameters of the completely relaxed 4–21G ab initio geometries of more than 30 basic organic compounds are compared to experimental results. Some ranges for systematic empirical corrections, which relate 4–21G bond distances to experimental parameters, are associated with total energy increments. In general, for the currently feasible comparisons, the following corrections can be given which relate calculated distances to experimental r_g parameters and calculated angles to r_s-structures For CC single bond distances, deviations between calculated and observed parameters (r_g) are in the ranges of ?0.006(2) to ?0.010(2) Å for normal or unstrained hydrocarbons; ?0.011(3) to ?0.016(3) Å for cyclobutane type compounds; and +0.001(5) to +0.004(4) Å for CH₃ conjugated with CO. For CO single bonds the ranges are ?0.006(9) to +0.002(3) Å for CO conjugated with CO; and ?0.019(3) to ?0.027(9) Å for aliphatic and ether compounds. A very large and exceptional discrepancy exists for the highly strained ethylene oxide, r_s — r_e = ?0.049(5) Å and in CH₃OCH₃ and C₂H₅OCH₃ the r_s — r_e differences are ?0.029(5), ?0.040(10) and ?0.025(10) Å. Some of these discrepancies may also be due to deficiencies of the microwave substitution method caused by atomic coordinates close to inertial planes. For CN bonds, two types of NCH₃ corrections are from +0.005(6) to ?0.006(6) and from ?0.009(2) to ?0.014(6) Å; and the range for NCO is +0.012(3) to +0.028(4) Å. For isolated CC double bonds the range is + 0.025(2) to +0.028(2) Å. For conjugated CC double bonds the correction is less positive (+0.014(1) Å for benzene). For CO double bonds the corrections are ?0.004(3) to +0.003(3) Å. For bond angles of type HCH, CCH, CCC, CCO, CCO, OCO, NCO and CCC the corrections are of the order of magnitude about 1–2° (or better). Angles centered at heteroatoms are less accurate than that, when hydrogen atoms are involved. Differences in HOC and NHC angles were found in a range of ?2.3(5)° to ?6.2(4)°.     

Microwave spectrum of the s-trans form of 3-pyridinecarbaldehyde

The microwave spectra of the ground state and one excited state of the ON s-trans form of 3-pyridinecarbaldehyde have been measured and assigned. The ground state rotational constants and dipole moment components are: A = 5417.8, B = 1583.289, C = 1225.389 (in MHz) and ¦μ_a¦ = 1.35, ¦μ_b¦ = 0.5 (in debye). The excited state most probably belongs to the C₃C torsion, for which the vibrational frequency is estimated to be 135 ± 30 cm^?1.     

Thermodynamics of solid solution formation in NiOMgO and NiOZnO

High-temperature calorimetric measurements of the enthalpies of solution in molten 2PbO · B₂O₃ of (Ni_xMg_1?x)O and (Ni_xZn_1?x)O permit the calculation of the enthalpy of the zincite to rocksalt transformation in ZnO, and the enthalpies of mixing, relative to rocksalt standard states, in the two solid solution series. The enthalpy of the zincite to rocksalt transformation is 24,488 ± 3,592 J mole^?1 with a corresponding positive entropy change of 0.48 ± 3.3 J K^?1 mole^?1. The small positive entropy change for the transformation necessitates a very flat and perhaps negative $\text{dP}\text{dT}$ slope for the phase boundary. Both solid solutions, when referred to rocksalt standard states, show negative enthalpies of mixing. For (Ni_xMg_1?x)O the negative enthalpies of mixing are fitted by a subregular model, where ΔH_mix = X_AX_B(BX_A + AX_B), with A = ?21,971 ± 4,953 J mole^?1 and B = ?5103 ± 1151 J mole^?1. The associated negative excess entropies of mixing, calculated from the heats of mixing and previously measured activity-composition relations, are similarly modeled with A = ?10.7 J K^?1 mole^?1 and B = + 1.1 J K^?1 mole^?1. Negative enthalpies of mixing in (Ni_xZn_1?x)O conform to a regular solution model with W = ?13520 ± 5581 J mole^?1. The negative enthalpies of mixing are interpreted in terms of a tendency toward ordering in the solid solutions, the proposed ordering scheme finding support in spectroscopic, structural, and magnetic data. These tendencies toward order are used to explain observed phase relations and thermodynamic properties in some other systems containing a transition metal cation and another ion of similar size, namely carbonates, hydrated sulfates and the systems CuOMO (M = Mg, Co, Ni).     

Synthesis,Crystal Structure,and Hydrogen Bonding of μ‐Hydroxo‐μ‐peroxo‐bis[bis(ethylenediamine)cobalt(III)] Squarate

Black‐brown needle‐shaped single crystals of [Co₂(en)₄(O₂)(OH)][C₄O₄]_1.5 · 4H₂O (en = ethylenediamine) were prepared in aqueous solution at room temperature [space group P$\bar{1}$ (no.2) with a = 800.20(8), b = 1225.48(7), c = 1403.84(9) pm, α = 100.282(5), β = 94.515(7), and γ = 95.596(6)°]. The Co³⁺ cations [Co(1), Co(2)] are coordinated in an octahedral manner by four nitrogen atoms stemming from the ethylenediamine molecules and two oxygen atoms each from a hydroxo group and a peroxo group, respectively. Both Co³⁺ coordination polyhedra are connected by a common corner and by the peroxo group leading to the dinuclear [(en)₂Co(O₂)(OH)Co(en)₂]³⁺ cation. The squarate dianions, not bonded to Co³⁺, and the [(en)₂Co(O₂)(OH)Co(en)₂]³⁺ cations are linked by hydrogen bonds forming a three‐dimensional supramolecular network containing water molecules. Magnetic measurements revealed a diamagnetic behavior indicating a low‐spin electron configuration of Co³⁺. The UV/Vis spectra show two LMCT bands [π*(O₂^2–) → d_σ*(Co³⁺)] at 274 and 368 nm and the d–d transition (¹A_1g → ¹T_1g) at 542 nm. Thermoanalytical investigations in air show that the compound is stable up to 120 °C. Subsequent decomposition processes to cobalt oxide are finished at 460 °C.     

The dinuclear unit μ-aqua-bis(μ-carboxylato)dimetal. X-ray structure and magnetism of cobalt and nickel(II) compounds containing bridging carboxylato groups and a bridging water molecule

The syntheses, characterization, X-ray structure and magnetism of a number of dinuclear compounds, with general formula M₂(μ-OH₂)(μ-O₂CR)₂(O₂CR)₂(tmen)₂ are described. In this formula M = Co(II), Ni(II), R = CH₃, CH₂Cl, CHCl₂, and CCl₃, and tmen stands for N,N,N′,N′-tetramethyl-1,2-diaminoethane.The X-ray structures of two examples, M = Co and R = CCl₃(I) and M = Co, Ni and R = CH₂Cl(II) are described in detail. Compound I crystallizes in space group P2₁/c, with a = 23.610(7), b = 10.439(2) and c = 17.920(4) Å, β = 110.43(4)° and Z = 4. Using 5196 measured reflections collected on a diffractometer with graphite monochromatized Mo-Kα radiation, the structure was refined to R = 0.089. The dimeric units Co₂(OH₂)(O₂CCl₃)₂ [Co … Co = 3.696(3) Å, angle CoOCo = 116.1(6)°] resemble very much those of earlier reported structures with M = Ni, Co and other bridging carboxylato anions. Apart from the two bridging carboxylato anions, two monodentate CCl₃CO⁻₂ anions are present, in addition to the normal bidentate tmen ligands, completing the octahedral geometry for each metal ion. The dimeric structure, with the bridging water ligand, appears to be highly stabilized by intramolecular hydrogen bonding with one of the oxygens of the monodentate CCl₃CO⁻₂ ligands (O … O contacts of 2.56–2.60 Å). This stabilization by hydrogen bonding appears to be very similar to the proposed hydrogen bonding in hemerythrine, in which the coordinated dioxygen seems to be hydrogen bonded with the bridging -OH group.Compound II has essentially the same basic structure; it crystallizes also in the space group P2₁/c, with a = 16.034(7), b = 13.114(7), c = 15.344(7), β = 91.20(4) and Z = 4. From 4701 measured reflections the structure was refined to R = 0.043. The dimeric units exhibit a Co-Ni distance of 3.596(1) Å, with a Ni-O-Co angle of 116.5°. The slightly smaller distances around Ni(II) made distinction from Co(II) possible.The metal ions in these Co and Ni compounds are antiferromagnetically coupled, just as the Fe ions in hemerythrine. This antiferromagnetic interaction has been studied by low-temperature magnetic susceptibility measurements. The magnitude of the coupling appears to vary as a function of the metal, the M … M distance and the MOM angle.     

Reaction of oxygen with a binuclear cobalt(II) hexaphosphine complex. Single-crystal X-ray structure of an extended chain cobalt(II) hexaphosphine oxide system

Molecular oxygen reacts rapidly with Co₂Cl_4-x,(eHTP)^x+ [x = 0 or 2; eHTP = (Et₂PCH₂CH₂)₂PCH₂P(CH₂CH₂PEt₂)₂] in dry acetonitrile to produce in approximately 66% yield the fully-oxygenated phosphine oxide eHTP (eHTPO) Co(II) complex [Co(eHTPO)²⁺][CoCl₄²⁻. The X-ray structure on this novel system shows an extended chain system in which the monomeric repeating unit has an octahedral Co(II) centre. The eHTPO ligand is adopting an unusual conformation with the phosphine oxide groups P(2)P(1)P(3) (P(1) is one of the internal phosphorus atoms) forming a P(1)P(2) chelate to the metal atom while P(3) bridges to another Co(eHTPO)²⁺ monomer unit making up the extended chain, instead of acting as an independent bis chelating group. The third unique coordination site on the cobalt centre is occupied by a phosphine oxide group from the other half of the eHTPO ligand which bridges over to the cobalt centre forming a facial set of three PO donor ligands. This mixed bridging/chelating conformation gives rise to fused seven- and nine-membered ring systems with a CoCo separation of 7.613(0) Å between symmetry related cobalt sites on the extended chain. This structure is the first reported for a Co(R₃PO)₆ⁿ⁺ (R = alkyl, phenyl) system.     

Isodimorphism of the salts 2RbCl · MIICl2 · 2H2O (MII = Mn,Fe, Co,Cu)

The three-component systems RbClMnCl₂H₂O, 2RbCl · CoCl₂ · 2H₂O2RbCl · CuCl₂ · 2H₂OH₂O, 2RbCl · CoCl₂ · 2H₂O2RbCl · MnCl₂ · 2H₂OH₂O have been studied at 25°C. In the 2RbCl · CoCl₂ · 2H₂O2RbCl · CuCl₂ · 2H₂OH₂O system, a discontinuous series of mixed crystals is formed and in the 2RbCl · CoCl₂ · 2H₂O2RbCl · MnCl₂ · 2H₂OH₂O system, a continuous series is present.The unit cell parameters of the 2RbCl · CoCl₂ · 2H₂O double salt were determined: a = 5.586(2) Å, b = 6.469(3) Å, c = 6.988(2) Å, α = 65.31(3)°, β = 87.69(3)°, γ = 84.65(4)°, volume 228.4 ų, Z = 1.The results obtained and discussed in conjunction with the crystal structure data suggest that for 2M^ICl · M^IICl₂ · 2H₂O type salts the triclinic structure is stable only when the large rubidium and cesium ions participate in combinations with non-Jahn-Teller metal(II) ions. In the cases of Jahn-Teller metal(II) ions or with potassium or ammonium ions a tetragonal structure is always stable.     

Small ring metallocycles : V. Crystal and molecular structure of hydrido-1,3-(1,1,3,3-tetramethyldisiloxanediyl)carbonylbis(triphenylphosphine)iridium(III), Me2SiOSiMe2Ir(H)(CO)(PPh3)2 · EtOH

The structure of the cyclo-metalladisiloxane, Me₂SiOSiMe₂Ir(H)(CO)(PPh₃)₂, has been determined by single crystal X-ray diffraction using Mo-K_α radiation. Data were collected to 20 = 45 ° giving 6060 unique reflections,of which 4582 had I ?3σ(I). The latter were used in the full-matrix refinement. Crystallographic data: space group, P$\text{1}$; cell constants: 12.604(7),12.470(4), 15.821(6) Å, 66.93(6)°, 105.34(7)°, 112.41(8)°;V 2095(3) ų; p(obs) 1.45 g/cm³; p(calc) 1.46g/cm³ (Z=2). The asymmetric unit consists of one iridium complex and one molecule of ethanol of salvation. The structure was solved by standard heavy atom methods and refined with all non-hydrogen atoms anisotrophic to final R factors, R₁ 0.034 and R₂ 0.042. The iridium metallocycle has approximate C_s symmetry with the mirror plane passing through the four-membered IrSiOSi ring. The average IrP, IrSi and SiO bond lengths are 2.38, 2.41, and 1.68 Å, respectively. The IrCO and CO bond lengths are 1.903(8) and 1.133(8). The H atom bonded to Ir was not located.The Ir atom is raised out of the basal, P₂Si₂ plane toward the carbonyl by about 0.26 Å. The most striking feature of the structure is the strain apparent in the four-membered ring. The internal angels are: 64.7 (SiIrSi), 96.8 (IrSiO), 97.8 (IrSiO), and 99.8 (SiOSi). In an unstrained molecule, the SiOSi angle is normally in the 130–150° range. It is proposed that the strain in the ring is consistent with the catalytic activity of the metallocycle.     

The isotropic temperature factors of Sr(Co1−xMnx)O3 (x = 0, 0.1, 0.5, 0.8, and 1.0)

The cubic perovskite Sr(Co_1?xMn_x)O₃ has a maximum value of a-axis at x = 0.3 and a change of spin state of Co⁴⁺ ion from low to high. To elucidate these properties, the isotropic temperature factor (B) of strontium, cobalt, manganese, and oxygen atoms for x = 0, 0.1, 0.5, 0.8, and 0.1 have been derived from powder X-ray diffraction measurements. The isotropic temperature factor of oxygen for x = 0, 0.1, and 1.0 is small and that for x = 0.5 and 0.8 is large. This fact suggests that the oxygen ion deviates from the center of the CoOMn bond in the solid solutions with $\text{x ≧ 0.3}$. Larger CoO₆ octahedra and smaller MnO₆ octahedra, which are connected by corner sharing of oxygens of the octahedron, are distributed statistically.     

Skew-trapezoidal bipyramidal diorganotin(IV) bischelates. Crystal structure of dimethylbis(2-pyridinethiolato-N-oxide)tin(IV)

Dimethylbis(2-pyridinethiolato-N-oxide)tin(IV), Me₂Sn(2-SPyO)₂, crystallizes in space group P2₁/c with a 9.877(3), b 11.980(4), c 13.577(3) Å, β 109.1(2)° and Z = 4. The structure was refined to R_F = 0.036 for 2263 Mo-K_α observed reflections. The coordination geometry at tin is a skew-trapezoidal bipyramid, with the oxygen [SnO 2.356(3), 2.410(4) Å] and sulfur [SnS 2.536(1), 2.566(1) Å] atoms of the chelating groups occupying the trapezoidal plane and the methyl groups [SnC 2.106(6), 2.128(7) Å] occupying the apical positions. The methyl-tin-methyl skeleton is bent [CSnC 138.9(2)°]. The SSnS angle is 77.8(1)°, but the OSnO angle is opened to 136.7(1)° to accommodate the intruding methyl groups. The carbontincarbon angles predicted from quadrupole splitting (^119mSn Mössbauer) and one-bond ¹¹⁹Sn¹³C coupling constant (solution ¹³C NMR) data agree closely with the experimental value.     

Structural and infrared spectroscopic characterization of Co6C(CO)12S2: a high-nuclearity carbido carbonyl cluster spontaneously formed from dicobalt octacarbonyl and carbon disulphide

Co₆C(CO)₁₂S₂ (I) has been isolated in crystalline form from the mixture of more than a dozen of carbonyl products formed when Co₂(CO)₈ reacts at room temperature with CS₂. Crystals of I are monoclinic with space group Cc, and lattice constants a  16.250(5), b  9.413(4), c  16.036(5) Å, β  116.77(4)°. Structure refinement gave R  0.034 for 1974 reflections. The CCo₆S₂ core of the molecule possesses idealized D_3h geometry. It is composed of a Co₆ trigonal prism, enclosing a C atom in the centre, and the triangular faces are capped symmetrically by the two S atoms. The core contains two sorts od CoCo distances: short one (2.432 Å) along the triangular edges, and long ones (2.669 Å) along the lateral edges. The average CoC distance is 1.94 Å, and the average CoS distance 2.192 Å.¹³CO-enriched samples were prepared photochemically and their IR spectra used in the assignment of the CO stretching frequencies. The CO stretching force constant was calculated to be 1670(2) Nm^-1.By the use of ¹³CS₂, I has also been obtained in a selectively carbido-¹³C-labelled form. The vibrational frequencies of the carbide atom were observed, and that at 819 cm^-1 (¹³C: 790 cm^-1) assigned to the species

, and that at 548 cm^-1 (¹³C: 535.5 cm^-1) to species E′. For the Co-C(carbide) force constant a value of 155 Nm^-1 was calculated. The cobalt—sulphur stretching frequencies were found at 309 cm^-1 (

) and 239 cm^-1 (E′). The CoS stretching force constant, 78 Nm^-1, is considerably lower than that obtained for SCo₃-(CO)₉, viz. 112 Nm^-1.     

Crystal structure of oxo(diperoxo)bipyridylmolybdenum(VI)

Yellow oxo(diperoxo)bipyridylmolybdenum(VI), C₁₀H₈MoN₂O₅, M_r = 332.1 crystallizes in the monoclinic space group P2₁/n, a = 6.261(3), b = 12.726(1) c = 13.752(3)A, β = 91.84(2)°, V = 1095.2(5)A³, Z = 4, D_c = 2.014(1) g/cm³, MoKα(λ = 0.7107A), μ = 11.8 cm^?1, T = 22(1)°C, R = 0.034, ωR = 0.040, number of reflections in least squares (F₀ > 2σ(F₀)) = 1125. The molybdenum coordination (distorted trigonal bipyramidal) is as in the corresponding chromium complex, C₁₀H₈CrN₂O₅ which has closely similar bond angles but is not isomorphous. The difference in MoN_apex and MoN_eq bond distances (2.312(5) and 2.199(5)A) is similar to that in the CrN_apex and CrN_eq distances (2.23(2) and 2.11(2)A). The MO distances for each peroxo ligand (ave. 1.910(2) and 1.950(2)A) are significantly different and slightly longer than those in the chromium complex as is the OO distance of 1.459(6)A. The latter is indicative of greater negative charge on the O₂ ligands, approaching that of O^2?₂ in the molybdenum complex.     

ESR study of the generation and decay of peroxy radicals in mechanically destructed polyamide 6

Polyamide 6 has been mechanically destructed in vacuo. At -70°, the ESR spectrum corresponds to the sum of the component spectra of three radicals NH?HCH₂, ·CH₂NHCO, and ·CH₂CONH. After introducing air into the ampoule, the spectrum changes even at -70°; the changes have been studied up to 0°. The spectrum of the peroxy radical ROO· (with line width 1.57 mT, g₁ = 2.0089 and g_| = 2.0301) predominates.