The synthesis of P-chiral optically pure phosphorothioates,phosphorotrithioates, phosphoroselenothioates,methanephosphonothioates, and methylphenylphosphinothioates

Enantiomers of representative alkyl esters of phosphorothioic ( 7 ), phosphorodithioic ( 6 ), phosphorotrithioic ( 11 ), phosphoroselenothioic ( 9 ), methanephosphonothioic ( 28 ), methanephosphonodithioic ( 25 ), and methylphenylphosphinothioic ( 31 ) acids were prepared from corresponding pure diastereoisomers of N-[R(+)- or S(-)-α-methylbenzyl] phosphamidochalcogenates (e.g. 2 , 3 , 12 , 17 , 23 , 26 , and 30 ) via PN → PX conversion, which has been proved to proceed with full retention of configuration at phosphorus.     

Magnetic,Optical, and Electronic Properties of the Phosphide Oxides REZnPO (RE = Y,La–Nd,Sm, Gd,Dy, Ho)

Well‐shaped yellow to red transparent single crystals of the phosphide oxides REZnPO (RE = Y, La–Nd, Sm, Gd, Dy, Ho) were synthesized from the elements and ZnO in NaCl/KCl fluxes in sealed silica ampoules. Four structures (NdZnPO type, R3m) were refined from single crystal X‐ray diffractometer data: a = 388.5(2), c = 3032(1) pm, wR2 = 0.0380, 360 F² values for YZnPO, a = 394.6(2), c = 3071(1) pm, wR2 = 0.0587, 226 F² values for SmZnPO, a = 392.2(2), c = 3056(1) pm, wR2 = 0.0262, 462 F² values for GdZnPO, and a = 389.33(6), c = 3030.5(4) pm, wR2 = 0.0453, 217 F² values for DyZnPO each with 14 variables per refinement. The structures are composed of alternate stacks of (RE³⁺O²⁻) and (Zn²⁺P³⁻) layers with covalent RE–O and ZñP bonding within and weak ionic bonding between the layers. The zinc and oxygen atoms have slightly distorted tetrahedral coordination by atoms of phosphorus and the rare earth element, respectively. According to the electron precise formulation RE³⁺Zn²⁺P³⁻O²⁻, these pnictide oxides are transparent in visible light. Susceptibility measurements on β‐CeZnPO, β‐PrZnPO, and GdZnPO reveal Curie‐Weiss paramagnetism with experimental magnetic moments of 2.31, 3.60, and 7.72 μ_B/RE atoms, respectively. β‐CeZnPO and β‐PrZnPO show antiferromagnetic order with Néel temperatures of 7.4 (Ce) and 2.2 (Pr) K. GdZnPO shows no magnetic ordering down to 2 K. Single crystal absorption spectra measured for REZnPO (RE = Y, La, Pr, Nd, Sm, Dy) in the NIR‐Vis region reveal unexpected variations for the optical band gap of these phosphide oxides. For RE = Pr, Nd, Sm, Dy, Ho f‐f electronic transitions with nicely resolved ligand‐field splittings are observed in the range 6000–20000 cm⁻¹. DFT band structure calculations show similarity between the valence bands of tetragonal and rhombohedral REZnPO as they possess mainly P‐3p character. In both cases, the conduction bands have mainly Zn‐4s character, but a significant contribution of RE‐5d occurs in rhombohedral REZnPO, which is responsible for a smaller optical band gap for the latter compounds. Variations of the energy gaps of tetragonal REZnPO can be explained by hybridization of Zn‐4s + RE‐5d + RE‐4f orbitals for the conduction band. DFT volume optimizations of α‐ and β‐PrZnPO show β‐PrZnPO to be more stable by 10.7 kJ mol⁻¹.     

Theoretical Study of Molecular Structure,Reactivity, Lipophilicity,and Solubility of N-Hydroxyurea,N-Hydroxythiourea,and N-Hydroxysilaurea

Ab initio molecular orbital methods at the CBS-QB3 level of theory have been used to study the structure and gas-phase stability of various tautomers and rotamers of N-hydroxyurea, N-hydroxythiourea, and N-hydroxysilaurea, their anions and protonated forms. The geometries of N-hydroxyurea, N-hydroxythiourea, and N-hydroxysilaurea, their anions and cations were optimized at the Becke3LYP/CBSB7 level of theory. For all compounds studied, the amidic form is computed to be substantially more stable than the iminolic tautomer. N-Hydroxyurea and its thio and sila derivatives are computed to behave as Nacids in the gas phase. These compounds are in gas-phase weak acids with a calculated acidity of about 1425 to 1355 kJ-mol^–1. Basicities increase in the order: N-hydroxyurea < N-hydroxythiourea < N-hydroxysilaurea. The most stable protonated structures are represented by several isomers with almost equal stability. Thus, in the N-hydroxyurea, N-hydroxythiourea, and N-hydroxysilaurea, both protonation at the double bonded (C=O, C=S and Si=O) oxygen and sulfur atoms, as well as the protonation at the N(H)OH nitrogen basic center is equally probable. The experimental pK _a value (10.6) of N-hydroxyurea and the computed value (9.7) for its monohydrated complex with the specifically hydrogen-bonded water molecule to the ionizable OH group are in a good agreement. The experimental partition coefficient of N-hydroxyurea is best reproduced by the Alog P_s method. The formation of nitroxide radical in the reaction of N-hydroxyurea and its sulfur and silicon substituted derivatives with the phenol radical is an exothermic process. Thus, the \bondN(H)OH moiety of these compounds may quench the structurally related tyrosyl radicals in the active site of ribonucleotide reductase.     

Stereochemical Definition of the Natural Product (6R,10R,13R, 14R,16R,17R,19S,20S,21R,24S,25S,28S,30S,32R,33R,34R,36S,37S,39R)‐Azaspiracid‐3 by Total Synthesis and Comparative Analyses

The previously accepted structure of the marine toxin azaspiracid‐3 is revised based upon an original convergent and stereoselective total synthesis of the natural product. The development of a structural revision hypothesis, its testing, and corroboration are reported. Synthetic (6R,10R,13R,14R,16R,17R,19S,20S,21R,24S,25S,28S,30S,32R, 33R,34R,36S,37S,39R)‐azaspiracid‐3 chromatographically and spectroscopically matched naturally occurring azaspiracid‐3, whereas the previously assigned 20R epimer did not.     

Synthesis of new chiral mono-, di-, tri-, and tetraalkylglycolurils

Two general procedures were developed for the synthesis of chiral N-mono-, N, N′-di-, N, N′ N″-tri-, and N, N′, N″, N′″-tetraalkylglycolurils based on the reactions of 4,5-dihydroxy-imidazolidin-2-ones or glyoxal with one or two moles of alkylureas, respectively, by acid catalysis. The reactions of N-monoalkyl- and N, N′-dialkylureas with glyoxal proceed regioselectively. The mechanism of these reactions was suggested and partly confirmed by quantum-chemical calculations and experimental data. The enantiomeric separation of some chiral glycolurils by chiral-phase HPLC was carried out for the first time.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 680–692, March, 2005.     

Organometallic gold(I)-pentafluorophenyl-P,O, As,S, TPA,dppm, dppe,dppa-coordinating-phosphines: synthesis and detailed spectroscopic characterisation

[Au(C₆F₅)(tht)], which on reaction with P, O, S-coordinating phosphines in CH₂Cl₂ medium leads to [Au(C₆F₅)(X)] [X = PPh₃ H, (1a), oMe, (1b), pMe, (1c), mMe, (1d), AsPh₃ (2), OPPh₃ (3), SPPh₃ (4), dppm, dppe, dppa = diphenylphosphino-methane,-ethane,-ammine(5, 6, 7), TPA = 135-tetraaza-7-phosphino adamentane(8), Py4H (9a), 4Bu (9b), 4Ac (9c), tht = tetrahydrothiophen, C₆F₅ is the pentafluorophenyl ring]. The maximum molecular peak of the corresponding molecule is observed in the ESI mass spectrum. I.r. spectra of the complexes show –C = C– and C₆F₅ stretching near at 1610 and 1510, 955, 800 cm⁻¹. The ¹H-n.m.r. spectra as well as ³¹P- (¹H)n.m.r. suggest solution stereochemistry, proton movement, phosphorus proton interaction. ¹³C-n.m.r. spectrum reflect the carbon skeleton in the molecule. In the ¹H–¹H COSY spectrum of the present complexes and contour peaks in the ¹H–¹³C-HMQC spectrum, assign the solution structure and stereoretentive conformation in each step.     

Asymmetric Total Synthesis of (11R, 12S, 13S, 9Z, 15Z)-9, 12, 13-Trihydroxyoctadeca-9, 15-dienoic Acid,a self-defensive agent against rice-blast disease

The Diels-Alder adduct of furan and 1-cyanovinyl (1′R)-camphanate was converted into methyl [(tert-butyl)-dimethylsilyl 5-deoxy-2, 3-O-isopropylidene-β-L -ribo-hexofuranosid] uronate ((+)- 4 ). Reduction with diisobutyl-aluminium hydride gave the corresponding aldehyde which was condensed with the ylide derived from triphenyl-(propyl)phosphonium bromide to give (1R, 2S, 3S, 4S)-1-[(tert-butyl)dimethylsilyloxy]tetrahedro-2, 3-(isopropyl-idenedioxy)-4-[(Z)-pent-2′ -enyl]furan ((+)- 7 ). Removal of the silyl protective group gave a mixture of the corresponding furanose that underwent Wittig reaction with the ylide derived from [8-(methoxycarbonyl)-octyl]triphenylphosphonium bromide to yield methyl (11R, 12S, 13S, 9Z, 15Z)-13-hydroxy-11, 12-(isopropylidene-dioxy)octadeca-9, 15-dienoate ((?)- 9 ). Acidic hydrolysis, then saponification afforded (11R, 12S, 13S, 9Z, 15Z)-11, 12, 13-trihydroxyoctadeca-9, 15-dienoic acid ( 1 ).     

A density functional theory study on boundary of “superreduced” transition metal carbonyl anions [M(CO)n](M=Cr, n=5, 4, 3, z=2, 4, 6; M=Mn, n=5, 4, 3, z=1, 3, 5; M=Fe, n=4, 3, 2, z=2, 4, 6; M=Co, n=4, 3, 2, z=1, 3, 5)

A nonlocal density functional theory (DFT) method has been applied to the calculations on optimized geometry, Mulliken atomic net charges and interatomic Mulliken bond orders as well as total bonding energies (E) in the binary transition metal carbonyl anions with different reduced states [M(CO)_n]^z− (M=Cr, n=5, 4, 3, z=2, 4, 6; M=Mn, n=5, 4, 3, z=1, 3, 5; M=Fe, n=4, 3, 2, z=2, 4, 6; M=Co, n=4, 3, 2, z=1, 3, 5). For comparison of relative stability, a relative stabilization energy D is defined as D=E([M(CO)_n]^z−)−nE(CO). The calculated C–O distances are lengthened monotonously with the increase of the anionic charge, but the M–C distances are significantly lengthened only in the higher reduced states. The relative stabilization energy calculated is a considerable negative value in the lower reduced states, but a larger positive value in the higher reduced states. The DFT calculations show that with the increase of the anionic charge, the Mulliken net charges on the M, C, and O atoms all increase, however, an excess of the anionic charge is mainly located at the central metal atom. The calculated C–O Mulliken bond orders decrease consistently with the increase of the anionic charge, but the M–C bond orders exhibit an irregular behavior. However, the total bond orders calculated clearly explain the higher reduced states to be considerably unstable. From analysis of the calculated results, it is deduced that the stability of the binary transition metal carbonyl anions [M(CO)_n]^z− studied are associated with the coordination number n and the anionic charge z, further, it is possible for the anions studied to be stable if n≥z, conversely, it is impossible when n<z.     

Thermodynamics of Coordination Bonds in Metal closo-Heteroclusters of the Endofullerene Type M@N k B r C s n – (m = k + r + s = 12, 24, or 28; n = 0–4), Where M = Li,Mg, Al,Ti, Zr,Hf, V,Nb, Mo,Ru, Rh,Ir, Ta,Pt, Pd,and Au

The energy of coordination-induced stabilization and the enthalpy of formation of gaseous metal closo-heteroclusters of the M@N _k B _r C _s ^{n –} type (m = k + r + s = 12, 24, or 28; n = 0–4), where M = Li, Mg, Al, Ti, Zr, Hf, V, Nb, Mo, Ru, Rh, Ir, Ta, Pt, Pd, and Au, were estimated in terms of a structural-thermodynamic model. The stabilizing role of metals in clusters was demonstrated. The energies D ₀ of M–N, M–B, and M–C bonds were found to be underestimated by the MO LCAO method at the HF/6-31G* level.     

Design,synthesis, anticancer,antibacterial, and antifungal evaluation of 4-aminoquinoline-1,3,5-triazine derivatives

A series of 4-aminoquinoline 1,3,5-triazine derivatives were synthesized and evaluated for anticancer activity against cancer cell lines HeLa, MCF-7, HL-60, HepG2 where these derivatives exert significant anticancer activity. The molecules found nontoxic against MCF-12A. The molecules also showed potent inhibition of EGFR-TK as compared to eroltinib in enzyme-based assay. The newly synthesized derivatives were screened for their in vitro antibacterial and antifungal activity against Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, Proteus vulgaris, Escherichia coli, Pseudomonas aeruginosa and Candida albicans, Aspergillus niger, Aspergillus fumigatus using cefixime and fluconazole as standard. Antibacterial screening results suggest that compound 7c showed potent activity against S. aureus, P. aeruginosa, and P. vulgaris. In antifungal screening, compound 7b showed significant activity against A. niger, A. fumigatus and moderate activity against C. albicans.     

Syntheses and Crystal Structures of LaRhMg,CeRhMg, PrRhMg,and NdRhMg

New intermetallic rare earth compounds LaRhMg, CeRhMg, PrRhMg, and NdRhMg were prepared by reaction of the elements in sealed tantalum tubes in a high‐frequency furnace. The compounds were investigated by X‐ray diffraction both on powders and single crystals. LaRhMg crystallizes with the LaNiAl type structure, space group Pnma, Z = 8, a = 760.1(2), b = 419.92(8), c = 1702.6(2) pm, wR2 = 0.0482, 740 F² values and 38 variable parameters. The cerium compound adopts the ZrNiAl structure: P6¯2m, Z = 3, a = 752.3(1), c = 417.6(1) pm, wR2 = 0.0497, 250 F²2 values and 17 variable parameters. PrRhMg and NdRhMg crystallize with the TiNiSi type: Pnma, Z = 4, a = 721.62(7), b = 415.98(4), c = 869.47(8) pm, wR2 = 0.1864, 440 F² values, 20 variables for PrRhMg and a = 720.6(1), b = 417.6(1), c = 868.8(1) pm, wR2 = 0.0779, 425 F² values, 22 variables for NdRhMg. Refinements of the occupancy parameters revealed mixed Mg/Rh occupancy for the magnesium sites of the cerium and the neodymium compound leading to the compositions CeRh_1.262(8)Mg_0.738(8) and NdRh_1.114(9)Mg_0.886(9) for the investigated single crystals. From a geometrical point of view, the four crystal structures are built up from different rhodium centered trigonal prisms. The rhodium and magnesium atoms form three‐dimensional [RhMg] networks in which the rare earth metal atoms are located in different types of channels. The networks show Rh—Mg and Mg—Mg bonding.     

Derivational,Structural, and Biological Studies of Some New Pyrazolyl,Isoxazolyl, Pyrimidinyl,Pyridazinyl, and Pyridopyridazinyl from 4‐Substituted Antipyrine

(1,5‐Dimethyl‐3‐oxo‐2‐phenyl‐2,3‐dihydro‐1H‐pyrazol‐4‐yl)carbono‐hydrazonoyl dicyanide was used as a key intermediate for the synthesis of novel pyrazole, isoxazole, pyrimidine, and pyridazine derivatives. The newly synthesized compounds were characterized by elemental analyses and spectral data (IR, ¹H‐NMR, ¹³C‐NMR, and mass spectra). The compounds were tested for their in vitro antibacterial activity against Gram‐positive bacteria as (Staphylococcus aureus and Bacillus subtilis ) and Gram‐negative bacteria (Pseudomonas aeruginosa and Escherichia coli ). The investigated compounds were tested against two strains of fungi Botrytis fabae and Fusarium oxysporum using diffusion agar technique. The biological results showed clearly that most of the synthesized compounds revealed mild to moderate activity against the used microorganisms.     

Synthesis,Structure, and Characterization of [FeIIILCl3] (L = 1, 4, 8‐Triazacycloundecane, 1, 4, 7‐Triazacyclononane)

The structures of [Fe^III(tacud)Cl₃] ( 1 ) and [Fe^III(tacn)Cl₃] ( 2 ) (tacud = 1, 4, 8‐triazacycloundecane, tacn = 1, 4, 7‐triazacyclononane) are reported. Both compounds crystallize in the orthorhombic space group Pnma with a = 12.5570(9), b = 12.0028(9), c = 8.2577(6) Å, V = 1244.59(16) ų, and Z = 4 for 1 and a = 12.095(4), b = 11.125(4), c = 7.963(3) Å, V = 1071.5(6) ų, and Z = 4 for 2 . The structures of 1 and 2 feature iron(III) in distorted octahedral arrangement with three facially coordinated nitrogen ligands and three chlorides. Bidirectional intermolecular hydrogen bonding between N–H groups and coordinated chlorides is seen for 1 and 2 . Compound 1 is the first example of iron(III) bonded to tacud and compound 2 is only the second structure reported of a 1:1 complex between iron and tacn. The Fe^3+/2+ redox couple for 1 is observed at E_1/2 = 0.25 V (ΔE_p = 99 mV), and for 2 at E_1/2 = 0.09 V (ΔE_p = 108 mV) versus NHE in DMF at 298 K. Comparison of structural, magnetic, and electrochemical properties for 1 and 2 reveal subtle differences consistent with the stronger coordinating properties of tacn relative to tacud.     

Molecular Structure of the Macrocyclic Ligand Complex (5, 7, 12, 14-Tetraethyl-7, 14-Dimethyl-1, 4, 8, 11-Tetraazacyclotetra Decane) Nickel (II) Perchlorate

The structure of macrocyclic ligand complex, (5, 7, 12, 14-tetraethyl-7, 14-dimethyl-1, 4, 8, 11-tetraazacyclotetra decane)·Ni^II·(ClO₄)₂ has been determined by X-ray diffraction with three dimensional counter data. This compound, C₂₀H₄₄N₄Ni^II·(ClO₄)₂, crystallizes in orthorhombic space group Pbca, with cell parameters a=14.369, b=11.752, c=16.207 A, V=2736.8 A³, determined from Syntex Pl autodiffractomter. The formula weight (598.21) and a measured density of 1.45 gm cm^?3 (by flotation) indicate the presence of four molecules per unit cell (D_c=1.452 gm cm^?3). The structure was solved, using Patterson and Fourier methods and refined by full-matrix least-squares techniques to a reliability index, R(F) of 0.09, based on 1480 independent observed data corrected for absorption, L-p factors. In this molecule, in addition to the usual covalent and ionic bonds, there exist two hydrogen bonds between the perchlorate ions and the amine groups. The Ni and the four N atoms are coplanar. The six membered ring subtends a larger angle (93.5(3)°) over the Ni atom than the five membered ring (86.5(3)°) does. The former belongs to the chair form and the latter pertains to the gauche form.     

A Theoretical Study of LiHe+ n , NaHe+ n , and MgHe+ n Complexes, with n=1, 2, 3, 4

The LiHe⁺ _n , the NaHe⁺ _n , and the MgHe⁺ _n complexes with n=1, 2, 3, 4 were studied using ab initio calculations with the MP2/6-311+G(3df, 3pd) method. The complexes are found to be stable. For the n=1 complexes, previous results were available and the calculations performed are in good agreement with those results. This lends credibility to the results obtained for the complexes with higher n.     

Three New Lanostane Triterpenoids,Inonotsutriols A,B, and C,from Inonotus obliquus

Three new lanostane‐type triterpenoids, inonotsutriols A ( 1 ), B ( 2 ), and C ( 3 ) were isolated from the sclerotia of Inonotus obliquus (Pers .: Fr.) (Japanese name: kabanoanatake; Russian name: chaga). Their structures were determined to be (3β,21R,24S)‐21,24‐cyclolanost‐8‐ene‐3,21,25‐triol ( 1 ), (3β,21R,24R)‐21,24‐cyclolanost‐8‐ene‐3,21,25‐triol ( 2 ), and (3β,21R,24S)‐21,24‐cyclolanosta‐7,9(11)‐diene‐3,21,25‐triol ( 3 ) on the basis of NMR spectroscopy including 1D and 2D experiments (¹H,¹H‐COSY, NOESY, HMQC, and HMBC) and EI‐MS.     

The Synthesis of 4b, 5, 12, 12a-Tetrahydro-5, 12-ethano-13H-indeno[2,3-b]anthracenes, 4b, 5, 10, 10a - tetrahydro-5,10-ethano-11H-indeno[2,3-b]naphtalenes and 1,2,3,4,4a, 9a-Hexahydro-1,4-(peri-naphthaleno)-fluorenes

The synthesis of endo- and exo-13-oxo-4b, 5, 12, 12a-tetrahydro-5, 12-ethanoindeno[2,3-b]anthracene ( 23 ; Schemes 1 and 2), exo- and endo-11-oxo-4b, 5, 10, 10a-tetrahydro-5, 10-ethano-indeno[2,3-b]naphthalene ( 31 ; Scheme 3), 1,2,3,4,4a,9a-hexahydro?1,4-(peri-naphthaleno)-fluoren-9-one (36; Scheme 4), and the corresponding hydrocarbons of the stereoisomeric ketone pairs 23 and 36 , is described.     

Pyridyl-, bipyridyl-, and terpyridyl-functionalised azamacrocycles

Abstract

A series of azamacrocycles which have been N-functionalised with pendent pyridylmethyl-(pyCH₂-), bipyridylmethyl-(bipyCH₂-) and terpyridylmethyl- (terpyCH₂-) arms have been synthesised and characterised, and some of their coordination chemistry with transition metal ions is reported. By attaching the pendent-arms at the 5- rather than the 6-position of the py, bipy and terpy, new ligands are generated which can be used to form polynuclear metal complexes in a controlled and systematic fashion. Fluorescent pH and transition metal ion sensors have been developed by reacting the azamacrocyclic N-pendent bipyCH₂ arm(s) with cis-[Ru(bipy)₂Cl₂], to give macrocycles with up to four attached [Ru(bipy)₃]²⁺ groups. That based on 1,4,7-triazacyclononane (9N3), with three attached [Ru(bipy)₃]²⁺ groups, has a first photo excited state pK_a of 7.1, and is a useful fluorescent sensor for physiological pH at below micromolar concentrations. The analogous derivative of cyclam (1,4,8,11-tetraazacyclotetradecane) carrying four [Ru(bipy)₃]²⁺ groups has a first photo excited state pK_a of 5.7, allowing kinetic and thermodynamic fluorescence studies of metal ion uptake by an azamacrocycle at neutral pH without complications from protonated species. A pre-organised hexadentate tris(2,2′-bipyridyl) chelating ligand, 1,4,7-tris(2′,2″-bipyridyl-5′-ylmethyl)-1,4,7-triazacyclononane (L) has been developed, and crystal structures of mononuclear complexes [M(LH)]³⁺ (M = Ru, Cu) are reported. In [M(LH)]³⁺ the azamacrocyclic N-atoms are non-coordinating to M, but have a very high affinity for a single proton trapped in the macrocyclic cavity. An analogous and potentially nonadentate ligand has been developed based on 9N3 with three N-pendent terpyCH₂-arms.     

Highly Enantioselective,Organocatalytic, and Scalable Synthesis of a Rare cis,cis-Tricyclic Diterpenoid

A highly enantioselective, organocatalytic, and scalable synthesis of a very unusual cis-decalin-cis-hydrindane tricyclic diterpenoid system has been achieved. Despite the prevalent pharmacological space that the related trans,trans and trans,cis-systems occupy, there have been no reports of an asymmetric synthesis of the cis,cis systems in the literature until now. We demonstrate the flexibility of our approach not only through access to a diverse range of products, all of which are attained in exceptionally high selectivities, but also by showing their easy conversion to the corresponding trans,cis-system and other derivatives.     

Magnetische Untersuchungen der Carbide TiC,ZrC, HfC,VC, NbC und TaC

Zusammenfassung Die magnetische Suszeptibilität an sehr reinen Mono-Carbidproben wird in Abhängigkeit vom Kohlenstoffdefekt gemessen. Mit zunehmendem Kohlenstoffdefekt werden TiC_1–x , ZrC_1–x , HfC_1–x und VC_1–x paramagnetischer. Extrapolation auf stöchiometrisches TiC führt auf Diamagnetismus. NbC_1-x und TaC_1–x zeigen einen davon abweichenden Verlauf; deren Suszeptibilitäten nehmen im wesentlichen mit steigendem C-Defekt ab und erreichen diamagnetische Werte. Eine Vorstellung zur Deutung des Suszeptibilitätsverlaufes bei TiC_1–x , ZrC_1–x , HfC_1–x und VC_1–x unter Berücksichtigung der Bindungsenergie, bei Übergangsmetallen wird entwickelt und eine Erklärung für das magnetische Verhalten von Mischcarbiden gegeben.Mit 2 Abbildungen