Activation of the Si-H bond of Et2SiH2 in photochemical reaction with W(CO)6: Spectroscopic characterization of intermediate W-Si compounds and the revisited crystal structure of the bis{(μ-η-hydridodiethylsilyl)tetracarbonyltungsten(I)} complex [{W(μ-η-H-SiEt2)(CO)4}2]

The photochemical reaction of W(CO)₆ with diethylsilane has been used to generate new tungsten-silicon compounds varying in stability. The initially formed η²-silane intermediate complex [W(CO)₅(η²-H-SiHEt₂)], characterized by two equal-intensity doublets with ²J_H-H = 10 Hz at δ = 5.10 (¹J_Si-H = 217 Hz) and δ = −8.05 (¹J_W-H = 38 Hz, ¹J_Si-H = 93 Hz), was detected by the ¹H NMR spectroscopy (methylcyclohexane-d₁₄, −10 °C). The η²-silane complex was converted in the dark to give more stable species. One of them was characterized by two equal-intensity proton signals observed as doublets with ²J_H-H = 5.2 Hz at δ = −8.25 and −10.39 ppm. The singlet proton resonance at δ = −9.31 flanked by ²⁹Si and ¹⁸³W satellites (¹J_Si-H = 43 Hz, ²J_Si-H = 34 Hz, ¹J_W-H = 40 Hz) was assigned to the agostic proton of the W(η²-H-SiEt₂) group in the most stable compound isolated from the photochemical reaction products in crystalline form. The molecular structure of the bis{(μ-η²-hydridodiethylsilyl)tetracarbonyltungsten(I)} complex [{W(μ-η²-H-SiEt₂)(CO)₄}₂] was established by single-crystal X-ray diffraction studies. The tungsten hydride observed in the ¹H NMR spectrum at δ = −9.31 was located in the structure at a chemically reasonable position between the W and Si atoms of the W-Si bond of the bridging silyl ligand. The reactivity of photochemically generated W-Si compounds towards norbornene, cyclopentene, diphenylacetylene, acetone, and water was studied. As was observed by IR and NMR spectroscopy, the η²-silane ligand in the complex [W(CO)₅(η²-H-SiHEt₂)] is very easily replaced by an η²-olefin or η²-alkyne ligand.     

1,3-Diboraheterocycles as ligands in metal complexes involving endo-C-H bonds

Pentaalkyl-2,3-dihydro-1,3-diboroles possess unique properties in [L_nM(C₃B₂HR₅)] complexes because the neutral heterocycle functions as 4e donor toward metal complex fragments e.g. CpM (M = Co, Rh), (arene)Fe, and others. The specific feature of these complexes is its MeC-H group with methyl in the exo- and hydrogen in an endo-position, forming a bridging 3c,2e C-H-B or an axial M-C-H bonding. This reduces the strength of the C-H bond, and thus complexes of this type exhibit a high reactivity and synthetic potential. Various complexes with a MeC-H group between identical boron centers have been analyzed by X-ray diffraction and NMR studies regarding the bonding of the endo-C-H in bridging or in axial position. The bond lengths of endo-C-H and B-C, the NMR shifts as well as the coupling constant J_C-H give information about the bonding situation. In the CpCo(C₃B₂HMeEt₄) sandwich the endo-hydrogen could not be located, its ¹H NMR spectrum shows a high-field quartet at −8.8 ppm, and a low J_C-H = 81 Hz indicates a weakening of the bond strength. Deprotonation leads to the anion, used as building block for oligo-decker complexes. The complex Ni(C₃B₂H₂Me₄)₂ having two endo-C-H bonds, exhibits a unique reactivity in loosing hydrogen at ambient temperature and forming 2,3,5-tricarba-hexaboranyl-nickel complexes. Only few complexes allowed to locate the endo-hydrogen in C-H-B position by X-ray diffraction studies, which is supported by calculations. The energy difference between bridging and axial positions is very small.The surprising formation of the slipped 34 VE triple-decker [(Cp^∗Ru)₂(μ-C₆B₄H₂Me₈)] as sideproduct was observed in the reaction of tetrameric (Cp^∗RuCl) with C₃B₂HMe₅ and zinc dust to improve the synthesis of the violet sandwich Cp^∗Ru(C₃B₂Me₅). The related chloro complex Cp^∗Ru(C₃B₂ClMe₄) is a postulated intermediate, however, its transformation into the dinuclear species must include the uptake of two hydrogen atoms, which is not yet clarified. The yellow bis(pentamethylcyclopentadienyl-ruthenium)-μ,η⁶:η⁶-hexahydro-tetraboranaphthalene has an unprecedented framework with a bridge-head diborane(4) unit, two additional boron atoms and two MeC-H groups each located between two different boron centers. The endo-hydrogen atoms were not found in the X-ray diffraction analysis, DFT calculations indicate their location in axial positions. ¹H NMR data confirm the presence of two endo-H atoms (showing a quartet at - 4.6 ppm), of which only one could be deprotonated by potassium.     

Synthesis of four stereoisomers of protected 1,2-epiimino-3-hydroxypropylphosphonates

Enantiomerically pure protected 1,2-epiimino-3-hydroxypropylphosphonates were synthesised from hydroxy-1-{[(R)- or (S)-1-phenylethyl]aziridin-2-yl}methylphosphonates via regioselective ring opening with acetic acid followed by a stereospecific intramolecular cyclisation of 3-acetoxy-1-mesyloxy-2-(1-phenylethyl)aminopropylphosphonates and hydrogenolytic removal of the 1-phenylethyl group in the presence of Boc₂O. The trans-isomers of 3-acetoxy-[N-(1-phenylethyl)-1,2-epiimino]propylphosphonates exist as a 2:1 mixture of invertomers, which were fully structurally characterised based on their ¹H and ¹³C NMR spectroscopic data. Large differences in the ¹J_C-P values in N-(1-phenylethyl)aziridine-2-phosphonates were noticed depending on the spatial arrangement of the nitrogen lone pair and the phosphorus atom (syn-periplanar—ca. 215 Hz; anti-periplanar—182 Hz).     

H-Ge bond activation by tungsten carbonyls: An experimental and theoretical study

The activation of the Ge-H bond and the formation of several hydride complexes, characterized by high-field resonances, have been detected during the ¹H NMR spectroscopy monitoring of the photochemical reaction of Et₃GeH and Et₂GeH₂ with W(CO)₆ and the norbornadiene complex [W(CO)₄(η⁴-nbd)]. The activation of the Ge-H bond of triethylgermane in the photochemical reactions of tungsten(0) complexes has been applied in the hydrogermylation of norbornadiene (nbd), which leads to the formation of endo-triethylgermylnorbornene as the major product. The complex [{W(μ-η²-H-GeEt₂)(CO)₄}₂] has been fully characterized by NMR spectroscopy and by a single-crystal X-ray diffraction study. Evidence for the hydride ligand of the W(μ-η²-H-GeEt₂) group has been provided by ¹H NMR spectroscopy (δ = −9.02, ¹J_H-W = 31 Hz) and by DFT calculations. A DFT study of the structural properties and ¹H NMR chemical shifts of several possible intermediate σ and hydride complexes formed during the photochemical reaction of W(CO)₆ and Et₂GeH₂ has been performed.     

Synthesis,structure and characterization of [Mg7(μ3-OCH2CH2OMe)6(μ-OCH2CH2OMe)6][Al(n-Bu)4]2 – A cationic heptanuclear magnesium complex consisting of discrete cations and tetrabutylaluminate anions

Dibutylmagnesium (contaminated with Al(n-Bu)₃; n_Mg:n_Al ca. 1:0.2) was found to react with MeOCH₂CH₂OH followed by the addition of PhSCH(Me)Ph in the presence of 0.2 equiv n-butyllithium yielding [Mg₇(μ₃-OCH₂CH₂OMe)₆(μ-OCH₂CH₂OMe)₆][Al(n-Bu)₄]₂ (1) as the principal product (yield 40–45% referred to MeOCH₂CH₂OH). The single-crystal X-ray diffraction analysis revealed that the centrosymmetric cationic heptamagnesium complex is built up from seven edge-shared MgO₆ octahedra. The [Al(n-Bu)₄]⁻ anions adopt approximately a tetrahedral AlC₄ symmetry. ¹H, ¹³C and ²⁷Al NMR spectroscopic measurements showed that in THF solution the structures both of the heptamagnesium complex and the tetrabutylaluminate anion are preserved and that there are no cation–anion interactions reducing the symmetry. The ²⁷Al resonance (151.6 ppm) was found to be very sharp (w_1/2 = 5 Hz), the coupling constant ¹J(²⁷Al,¹³C) amounts to 72.3 Hz.     

C-F?M interaction in anionic α-fluorovinyl rhenium oxycarbene complexes and their β-fluoroenolate analogs

The C-F?M⁺ interaction in anionic σ-(α-fluorovinyl)rhenium oxycarbene complexes, [RCFCFReC(O)R′(CO)₄]M (1-6), M = Na, Li, K is studied by ¹⁹F NMR in THF and Et₂O. The coordination of α-F to M⁺ results in an upfield shift of the corresponding ¹⁹F NMR signal and a decrease of ¹J_CF. The maximum shift is found for the Li salt of complex 4 in Et₂O (Δδ_Fα = 36.4 ppm), in which case a ⁷Li-¹⁹F spin-spin coupling is also observed (J_LiF = 40 Hz). The ΔE of C-F?M⁺ interaction and its effect on ¹⁹F shielding was further studied by DFT calculations using β-fluoroenolates as models, which confirmed a strong impact of CF-bond environment on the coordination ability of fluorine in these F,O-chelates. A compound with a β-fluoroenolate backbone but without rhenium, o-(α-fluorovinyl)phenolate 12, was prepared and studied by ¹⁹F NMR, and similarly showed indications of C-F?M⁺ interaction in THF solution. It is concluded that the donor ability of fluorine in the studied system is enhanced because of the conjugation of α-fluorovinyl group with the enolate π-system and back donation from the transition metal.     

Photovoltaic properties of new cyanine-naphthalimide dyads synthesized by ‘Click’ chemistry

Two novel cyanine dyads, in which a naphthalimide unit is attached to benzoindole ring of unsymmetric trimethine cyanine, have been synthesized via ‘Click’ reaction and characterized by ¹H NMR, ¹³C NMR, and MS-ESI. Under the illumination of AM 1.5 (75 mW cm⁻²), the power conversion efficiency of cyanine I reached 4.8% (J_sc = 14.5 mA cm⁻², V_oc = 0.50, FF = 0.49). The results show that the two cyanine dyes are promising sensitizers for nanocrystalline dye-sensitized solar cell.     

Cs4P2Se10: A new compound discovered with the application of solid-state and high temperature NMR

The new compound Cs₄P₂Se₁₀ was serendipitously produced in high purity during a high-temperature synthesis done in a nuclear magnetic resonance (NMR) spectrometer. ³¹P magic angle spinning (MAS) NMR of the products of the synthesis revealed that the dominant phosphorus-containing product had a chemical shift of −52.8 ppm that could not be assigned to any known compound. Deep reddish brown well-formed plate-like crystals were isolated from the NMR reaction ampoule and the structure was solved with X-ray diffraction. Cs₄P₂Se₁₀ has the triclinic space group P-1 with a=7.3587(11) Å, b=7.4546(11) Å, c=10.1420(15) Å, α=85.938(2)°, β=88.055(2)°, and γ=85.609(2)° and contains the [P₂Se₁₀]⁴⁻ anion. To our knowledge, this is the first compound containing this anion that is composed of two tetrahedral (PSe₄) units connected by a diselenide linkage. It was also possible to form a glass by quenching the melt in ice water, and Cs₄P₂Se₁₀ was recovered upon annealing. The static ³¹P NMR spectrum at 350 °C contained a single peak with a −35 ppm chemical shift and a ∼7 ppm peak width. This study highlights the potential of solid-state and high-temperature NMR for aiding discovery of new compounds and for probing the species that exist at high temperature.     

Wave packet and quasiclassical trajectory calculations for the N(D) + H2 reaction and its isotopic variants

The N(²D) + H₂(v = 0, j = 0) reaction and its HD and D₂ isotopic variants have been studied by means of quantum mechanical real wave packet and wave packet with split operator and quasiclassical trajectory methodologies on the potential energy surface of Ho et al. [J. Chem. Phys. 119 (2003) 6]. Total initial state-selected and final state-resolved reaction probabilities and product rotational distributions have been calculated for total angular momentum J = 0 in a broad range of collision energies. The real wave packet results are in very good agreement with the corresponding split operator wave packet calculations. A reasonable overall good agreement has been found between the wave packet and quasiclassical trajectory results. Integral cross-sections and thermal rate constants have been calculated from the wave packet reaction probabilities by means of standard J-shifting, refined J-shifting and uniform J-shifting methods in combination with the centrifugal sudden approximation for J > 0. Comparisons with available exact wave packet, quasiclassical trajectory and experimental results are made and discussed.     

Geometry determination of tetrasubstituted stilbenes by proton NMR spectroscopy

A simple spectroscopic method was applied to determine the geometry of tetrasubstituted alkenes. The observation of the ⁵J-coupling constants in proton NMR spectra on the ¹³C satellite signals could confirm the previous misassignment of 2,3-diphenylbutene. Hence, the (E)-isomer showed a 1.5 Hz coupling constant, whereas the (Z)-isomer showed a 1.1 Hz coupling constant. Based on this new assignment and a stereospecific preparation, we also propose a revision concerning the NMR data of 2,3-diphenyl-2,3-butanediol.     

Determination of Long Range Proton Carbon Coupling Constants by Modified Semi-Selective Two-Dimensional Inept: An Application in Stereochemical Analysis of Saccharides

Abstract

Long-range proton-carbon coupling constants are useful in the assignment of ¹³C NMR spectra and in stereochemical analysis. The measurement of vicinal coupling constants, ³J_C-H, and their interpretation based on appropriate Karplus-type relationships (e.g. for ³J_H-C-C-C or ³J_H-C-O-C)^1–3 provide valuable information in conformational studies of carbohydrates. Nevertheless, the use of ³J_C-H in carbohydrate studies is rather rare because their measurement is time consuming and analysis of ¹H-coupled ¹³C NMR spectra is complicated. However, 2D NMR methods ^4–6 that allow precise measurement of long-range couplings in a reasonable time have become available recently.     

Aqua bridged Cu2 dimer of a heptadentate N4O3 coordinating ligand: Synthesis,structure and magnetic properties

The N₄O₃ coordinating heptadentate imidazolidinyl phenolate ligand, H₃L (2-(2′-hydroxyphenyl)-1,3-bis[4-(2-hydroxyphenyl)-3-azabut-3-enyl]-1,3-imidazolidine) forms with Cu(II) a rare aqua bridged complex [{Cu₂(μ-L)(μ-H₂O)}₂](ClO₄)₂ · 4.5H₂O (1 · 4.5H₂O). Complex 1 · 4.5H₂O contains two crystallographically different but chemically equivalent dinuclear [Cu₂(μ-L)(μ-H₂O)]⁺ cationic units in the asymmetric unit. The copper atoms of each dinuclear unit are in a distorted square-pyramidal environment and are held together by phenolate, imidazolidinyl and aqua bridges with a Cu···Cu separation of av. 3.34 Å. The compound exhibits a very weak antiferromagnetic exchange interaction (J = −0.77 cm⁻¹, ? = −2 J?₁?₂) between the two copper(II) (S = 1/2) ions. The ¹H NMR spectrum of the complex shows a total of 17 hyperfine shifted peaks, as expected from the idealized C_s symmetry of the compound, spread over a very large window of chemical shift, spanning about 250 ppm. The complex, having an appropriate intermetallic separation for catechol binding, shows catecholase like activity in MeCN at 25 °C, with the aerobic oxidation of 3,5-di-tert-butylcatechol (3,5-DTBC) to 3,5-di-tert-butylquinone (3,5-DTBQ).     

Al NMR studies of Ce-Al mixed oxides: origin of 40 ppm peak

CeO₂-γ-Al₂O₃ mixed oxides have been prepared by using both co-precipitation and impregnation methods followed by calcination at 650°C and investigated by ²⁷Al MAS NMR, powder X-ray diffraction and temperature programmed reduction techniques to understand the nature of chemical interaction existing between CeO₂ and γ-Al₂O₃. The ²⁷Al NMR spectra of CeO₂-containing samples showed an additional peak placed at 40 ppm along with the two peaks at 68 and 6 ppm which originate from the tetrahedrally and octahedrally coordinated Al³⁺ ions present in γ-Al₂O₃. As the concentration of CeO₂ in the mixed oxide increased, the intensity of the 40 ppm peak increased and this was the prominent peak for CeO₂-rich mixed oxide samples. The origin of this 40 ppm peak is discussed and it is inferred that this peak is due to Al³⁺ ions, which are present in CeO₂ lattice, forming a solid solution.     

Synthesis and characterization of near-infrared absorption tin octabutoxy naphthalocyanines

Synthesis and characterization of a series of tin octabutoxy naphthalocyanines are presented, which show near infrared absorptions (900–930 nm) with high extinction coefficients (ca. 1 × 10⁵ M⁻¹ cm⁻¹). The position of the Q-band is more red-shifted with the heavier halogen, which corresponds to the HOMO–LUMO gaps calculated with density functional theory (0.932, 0.911, 0.905, 0.893 eV). The interaction with SnNc(OBu)₈Br₂ and C₆₀ moves the Q-band further to the infrared region (928 nm). In ¹¹⁹Sn NMR, the upfield shift (−120 ppm) of SnNc(OBu)₈I₂ represents a relatively electron-rich environment at the tin nucleus, and the ¹¹⁹Sn-resonance (237 ppm) of SnNc(OBu)₈F₂ is different from the other halides, where ¹¹⁹Sn–¹⁹F coupling, a triplet splitting (1:2:1), was observed with 1820 Hz coupling constant. In the optimized structures obtained with BLYP, the distortion angles vary from F to I (N–Sn–N angles 178.8°, 173.1°). The tin naphthalocyanine with the heavy halide ligand becomes more concave, and the Sn–X bond is located at a longer distance out of ring. The difference of the two axial bonds varies significantly from 0.003 to 0.104 Å with the change of the axial ligands from F to I. The distorted shape is larger in the order I > Br > Cl > F with increase of the atomic size (1.33, 1.15, 0.99, 0.71 Å, respectively) and decrease of electronegativity (2.21, 2.74, 2.83, 4.10, respectively). SnNc(OMe)₈X₂ has an electric dipole moment perpendicular to the naphthalocyanine plane, and the magnitudes are, 0.81, 0.50, 0.35 and 0.01 for F, Cl, Br and I, respectively. The transition dipole moment lies in the naphthalocyanine plane along the x- or y-axis perpendicular to the permanent dipole moment in the z-axis, which indicates a π → π^∗ ligand–ligand transition. The energies of the molecular orbitals which are mainly contributed to by the naphthalocyanine ring, including the HOMO and LUMO, are slightly changed as the axial ligands change from F to I.     

4,5-Bis[(triorganotin)thiolato]-1,3-dithiole-2-thione, (R3Sn)2(dmit), 4,5-bis[(triorganotin)thiolato]-1,3-dithiole-2-one, (R3Sn)2(dmio), compounds: Crystal structures of (cyclohexyl3Sn)2(dmio), (Ph3Sn)2(dmit) and (Ph3Sn)2(dmio)

The synthesis and crystal structures of 4,5-bis[(triorganotin)thiolato]-1,3-dithiole-2-thione, (R₃Sn)₂(dmit), 1, and 4,5-bis[(triorganotin)thiolato]-1,3-dithiole-2-one, (R₃Sn)₂(dmio), 2, compounds are reported. Compounds, (1 or 2: R = Ph or cyclohexyl, Cy), have been obtained from reaction of R₃SnCl with Cs₂dmit or Na₂dmio. The presence of the two tin centres in (2: R = Ph) is shown in the ¹³C NMR spectrum by the couplings of both Sn atoms to the dmio olefinic carbons with J values of 29.4 and 24.7 Hz. The δ¹¹⁹ Sn values for (1: R = Ph) and (2: R = Ph) differ by about 30 ppm, values being −20.7 and −50.1 ppm, respectively, in CDCl₃ solution. X-ray structure determinations for (1: R = Ph) and (2: R = Ph or Cy) reveal the compounds to have 4-coordinate, distorted tetrahedral tin centres. The dithiolato ligands, dmit and dmio, act as bridging ligands, in contrast to their chelating roles in R₂Sn(dmit) and R₂Sn(dmio). A further difference between R₂Sn(dmit) and R₂Sn(dmio), on one hand, and 1 and 2 on the other, is that intermolecular Sn-S and Sn-O interactions are absent in 1 and 2. However, weak intermolecular hydrogen bonding interactions are found in (1: R = Ph) [C-H?π] and in (2: R = Ph) [C-H?π and C-H?O].     

Synthesis, characterization and catalytic behaviors of water-soluble phosphine-sulfonato nickel methyl complexes bearing PEG-amine labile ligand

Two novel water-soluble phosphine-sulfonato nickel (II) methyl complexes [(P^O)NiMeL] (P^O = κ²-P,O-2-(2-MeO-C₆H₄)₂PC₆H₄SO₃, L = H₂N(CH₂CH₂O)_nMe, n = ca. 52, 2a; n = ca. 16, 2b) have been prepared and characterized by ¹H, ³¹P NMR and elemental analysis, and their reactivity towards ethylene was studied.     

A N NMR study of tautomerism in dimethyl dihydro-1,2,4,5-tetrazine-3,6-dicarboxylate

Dimethyl dihydro-1,2,4,5-tetrazine-3,6-dicarboxylate can exist either in 1,2- or 1,4-dihydro tautomeric forms. The ¹⁵N NMR spectra of dimethyl dihydro-1,2,4,5-tetrazine-3,6-dicarboxylate were measured at the ¹⁵N natural abundance level as well as in ¹⁵N doubly labelled selectively and in ¹⁵N completely labelled compounds (20% ¹⁵N). The J(¹⁵N,¹⁵N) value was determined in ¹⁵N completely labelled compounds (20% ¹⁵N) using 1D ¹⁵N INADEQUATE and was found to be 12.2 ± 0.2 Hz in deuteriochloroform, acetonitrile-d₃, DMSO-d₆ and CD₃OH. Very similar ¹⁵N chemical shifts and ¹J(¹⁵N,¹H) values were also observed in all the solvents. This indicates that compound 1 exists completely in the 1,4-dihydro tautomeric form (i.e., as dimethyl 1,4-dihydro-1,2,4,5-tetrazine-3,6-dicarboxylate) in all the solvents tested.     

The synthesis conditions, characterizations and thermal degradation studies of an etherified starch from an unconventional source

Starch isolated from an under-utilized legume plant (pigeon pea) was carboxymethylated. Influences of reaction parameters were investigated on the degree of substitution (DS) and the reaction efficiency (RE). Studies showed that optimal DS of 1.12 could be reached at reaction efficiency of 80.6% in isopropanol-water reaction medium (40 °C, 3 h). Scanning electron microscopy showed that after carboxymethylation, the granular appearance of the native starch was distorted. Wide-angle X-ray diffractometry revealed that crystallinity was reduced significantly after carboxymethylation. The infrared spectra revealed new bands in the carboxymethyl starch at ν = 1600, 1426 and 1324 cm⁻¹ which were attributed to carbonyl functional groups vibration, -CH₂ scissoring and OH bending vibration, respectively. Broad-band ¹³C NMR of carboxymethyl starch showed an intense peak at δ = 180.3 ppm which was assigned to carbonyl carbon on the carboxymethyl substituent on the AGU (Anhydroglucose Unit). DEPT (Distortionless Enhancement by Polarization Transfer) 135 NMR showed negative signals which correspond to methylene carbons on the AGU. Differential Scanning Calorimetry (DSC) suggests loss of crystallinity after carboxymethylation. Thermogravimetry (TG), Derivative Thermogravimetry (DTG) and Differential Thermal Analysis (DTA) show that thermal stability improved after carboxymethylation. The study provides information on the preparation and characterization of a biomaterial from a new source which could be used alone or in the preparation of other functional polymers for diverse polymer applications.     

A new [Ni4] distorted cubane assembly on four solvent derived μ3-OMe corners: Solvent dependent formation and cleavage of exogenous bridges

A new Ni₄ distorted cubane complex [Ni₄(μ₃-OMe)₄Q₄(MeOH)₄] (1) (where Q⁻ is the anion of 8-quinolinol) is obtained from the reaction of NaQ with Ni(OAc)₂ · 4H₂O in refluxing MeOH via solvent derived μ₃-OMe assisted self-assembly of four nickel(II) centres. The periphery of [Ni₄(OMe)₄] cubane is covered by four Q⁻ and four MeOH molecules. This methanol specific reaction is not supported in solvent glycinol (Hgl; NH₂(CH₂)₂OH), an amine substituted ethanol, producing monomeric [NiQ₂(Hgl)₂] · 2H₂O (2 · 2H₂O) instead and is able to cleave 1 to yield 2 · 2H₂O. The cryomagnetic susceptibility data of powdered 1 can be modeled by a two J equation yielding J₁ = −1.8(1) cm⁻¹, J₂ = 3.9(1) cm⁻¹ and g = 2.24.     

An AB3 high-resolution NMR spectrum in the solid state: 31P in P4S3

A high-resolution ³¹P NMR spectrum has been recorded in polycyrstalline tetraphosphorus trisulphide P₄S₃. The spectrum exhibits the resolved doublet and quartet structure characteristic of an AB₃ type spectrum, with chemical shift difference 185 ± 2 ppm and J = 70 ± 3 Hz.