T-butyl Derivative Research Articles

Nature of Large Temporal Fluctuations of Hydrogen Transfer Rates in Single Molecules.

Double hydrogen transfer was monitored in single molecules of parent porphycene and its tetra- t-butyl derivative using confocal fluorescence microscopy. The molecules have been embedded in a polymer matrix. Under such conditions, a significant fraction of the population reveals a huge decrease of the tautomerization rate with respect to the value obtained from ensemble studies in solution. This effect is explained by a model that assumes that the rate is determined by the reorganization coordinate that involves slow relaxation of the polymer matrix. The model provides indirect evidence for the dominant role of tunneling. It is proposed that tautomerization in single molecules of the porphycene family can be used to probe polymer relaxation dynamics on the time scale ranging from picoseconds to minutes.

Giant phototransistor response in dithienyltetrathiafulvalene derivatives

Thienyl-substituted tetrathiafulvalene (DTh-TTF, 1a) and a t-butyl derivative (1b) are prepared, and the remarkable photoresponse and memory effect in the transistors are investigated. Upon irradiation of light with a wavelength shorter than the absorption edge (535 nm), the threshold voltage of 1b shifts by as large as 57 V, and the drain current increases by 103 times. The photo generated conducting state is maintained for several tens of minutes but erased by the application of a large negative gate voltage.

Organic Transistors Based on Octamethylenetetrathiafulvalenes

Abstract Organic field-effect transistors (OFET) based on octamethylenetetrathiafulvalene (OMTTF) and the t-butyl derivative are investigated. The parent OMTTF shows poor transistor performance owing to the flat molecular arrangement, but the t-butyl substitution realizes standing molecular arrangement and high OFET performance. The tetracyanoquinodimethane (TCNQ) complex of OMTTF exhibits n-channel properties despite the strong donor ability of OMTTF.

Pharmacokinetics of 4‐aminopyridine derivatives in dogs

Blockade of potassium channels with 4-aminopryidine (4-AP) restores conduction to demyelinated axons and improves function. Unfortunately, 4-AP causes adverse effects and its clinical effects are unpredictable and limited. Derivatives of 4-AP have been tested in models of spinal cord injury in guinea pigs; three derivatives (methyl-, ethyl- and t-butyl carbamate derivatives) showed promise. This study investigates the safety and pharmacokinetics of these derivatives in dogs. Each derivative was administered orally to dogs starting at doses below effective doses in guinea pigs, and increasing the dose on sequential days. Routine blood work was performed prior to and 24 h after drug administration, blood samples were collected at intervals over 24 h after drug administration, and dogs were monitored for side effects. Derivative plasma levels were determined using high-pressure liquid chromatography. Cerebrospinal fluid (CSF) samples were taken to determine CSF levels. No adverse effects were seen even when using doses higher than those that improved conduction in spinal cord injured guinea pigs. Peak plasma levels occurred at 36.6 (ethyl), 87 (t-butyl) and 175 (methyl) min and plasma level was related to drug dose. Penetration of the central nervous system (CNS) was good, with CSF levels higher than plasma levels for the t-butyl derivative.

Perfectly “Anti-Apicophilic” Phosphoranes: Conversion of a 1-Hydro-5-carbaphosphatrane into 1-Alkyl- and 1-Aryl-5-carbaphosphatranes

1-Alkyl- and 1-aryl-5-carbaphosphatranes were prepared by the reaction of 1-hydro-5-carbaphosphatrane with nucleophiles and subsequent intramolecular oxidative cyclization. X-ray crystallographic investigation of the t-butyl derivative revealed that it has a perfectly “anti-apicophilic” arrangement. The apical 1 J PC coupling constants of the 5-carbaphosphatranes were extraordinarily large.

Bisquinoline-based fluorescent zinc sensors

Several bisquinoline derivatives, N,N'-bis(2-quinolylmethyl)-N,N'-dialkylethylnediamines (alkyl=methyl, ethyl, isopropyl and t-butyl), have been synthesized and their fluorescent responses toward zinc ion were investigated. These compounds exhibit zinc ion-induced fluorescence and their intensities decrease as the alkyl groups become larger. The t-butyl derivative (BQDtBEN) exhibited negligible fluorescence even in the presence of zinc ion. The fluorescence intensity of the zinc complex of the bisquinoline derivative (BQDMEN) is higher than that of TQEN (N,N,N',N'-tetrakis(2-quinolylmethyl)ethylenediamine), indicating that the TQEN-Zn complex has an intramolecular quenching mechanism due to the energy transfer among four quinoline rings and the remaining photoinduced electron transfer (PET) mechanism. Introduction of methoxy substituents into the quinoline ring shifted the excitation and emission wavelengths towards a lower-energy direction and increased the fluorescence intensity, which allows N,N'-bis(6-methoxy-2-quinolylmethyl)-N,N'-dimethylethylenediamine (6-MeOBQDMEN) to be used for cellular fluorescent microscopic analysis (lambdaex=331 nm, lambdaem=406 nm and phi=0.28 for 6-MeOBQDMEN-Zn complex).

Synthesis, structure and physical properties of a new TTFderivative containing a PPD part

To develop new photo-conducting multi-functional materials, a newtetrathiafulvalene (TTF) derivative containing a 2,5-diphenyl-1,3,4-oxadiazole (PPD) moiety,in which the PPD part is connected directly to the TTF part with a single bond, wassynthesized by the Pd(PPh3)4-catalized Stille coupling reaction. X-Ray crystal structureanalysis of the t-Butyl derivative (1) indicated the high planarity of the molecular skeleton andpossible conduction pathways along the side-by-side direction of the TTF parts. Fluorescencefrom the PPD part of 1 was almost quenched by the intramolecular electron transfer from theelectron-donating TTF part to the PPD part even when the PPD was irradiated by the excitationlight of 315 nm. The single crystalline sample of the TCNQ complex of 1 (1-TCNQ) wasprepared by a mixing method in CH3CN. The X-ray crystal structure analysis of 1-TCNQrevealed that there is PPD - TCNQ - TTF -type mixed stacking structure along the stackingdirection, resulting in insulating behaviour of this complex.

A 1H double-quantum magic-angle spinning solid-state NMR investigation of packing and dynamics in triphenylene and hexabenzocoronene derivatives

Solid-state 1H NMR methods employing very-fast magic-angle spinning (MAS) are applied to hexa-alkyl-substituted hexa- peri-hexabenzocoronenes (HBC) as well as an alkoxy-triphenylene derivative. Firstly for the HBC derivatives, the effect of changing the alkyl substituent from i-propyl to t-butyl on the structure adopted in the solid phase is investigated. From single-quantum MAS spectra, differences are apparent between the two cases, most notably in the aliphatic region, where for the t-butyl derivative, two peaks are resolved. The different structures adopted become much more apparent in rotor-synchronised two-dimensional double-quantum (DQ) MAS spectra, where definite proton–proton proximities can be identified, taking advantage of the significant resolution improvements afforded by the extension to a second frequency dimension. In both cases, different aromatic 1H resonances are resolved. This can be explained in terms of the differing degrees to which the protons experience the ring current due to the aromatic π-electrons of a nearby aromatic core. For the i-propyl derivative, the observed pattern of DQ peaks is the same as that observed in a previous study of an analogous hexa- n-dodecyl substituted HBC molecule, and thus the aromatic cores can be assumed to also pack as in unsubstituted HBC. For the t-butyl derivative, the steric bulk of the substituents leads to a different packing arrangement as identified in a separate X-ray single crystal investigation—the complicated arrangement of aromatic and aliphatic DQ peaks is shown to be in excellent agreement with this structure. For the triphenylene-based molecule, which exists in a liquid-crystalline phase at room temperature, the dynamics is investigated by an analysis of DQ MAS spinning-sideband patterns (recorded at a 1H Larmor frequency of 700.1 MHz), with, in particular, differential mobility along the alkyl chains being identified.

Recent developments in the synthesis of red dopants for Alq 3 hosted electroluminescence

An isopropyl substituted red fluorescent dye, 4-(dicyanomethylene)-2- i- propyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4 H-pyran (DCJTI), has been found to be a good dopant in a host MQ 3 matrix which produces organic EL devices with essentially identical luminance efficiency and chromaticity to that of the t-butyl derivative, DCJTB. The key intermediate, 4-(dicyanomethylene)-2-( I-propyl)6-methyl 4 H-pyran, involved in the synthesis of DCJTI is much easier to manufacture than that of DCJTB. In the interest of driving down the cost of OLED materials, DCJTI may prove to be a cheaper alternative for the red dopant DCJTB.

Complexes of salicylaldehyde acylhydrazones: Cytotoxicity, QSAR and crystal structure of the sterically hindered t-butyl dimer

A series of acylhydrazones of salicylaldehyde and their transition metal complexes, predominantly copper(II), have been prepared and characterized. The crystal structure of the Cu(II) complex of the sterically hindered t-butyl derivative contains a phenolato bridged dimer with the ligand coordinated as a tridentate moiety. QSAR analyses of the cytotoxicity of the chelators and their Cu(II) complexes reveals that solubility is the dominant factor for activity. Compounds display a maximum with respect to lipophilicity, allowing optimization of the bioactivity for both the ligands and their complexes. Copper complexes are significantly more cytotoxic than the metal-free ligands and complexes of other metals: Cu > Ni > Zn=Mn > Fe=Cr > Co.

Conformational equilibria of 2-substituted 1,3-dithio-5,6-benzocycloheptene and 1,3-dioxa-5,6-benzocycloheptene

The semiempirical PM3 method was used to study the Conformational equilibrium of the various chair, boat, twist and biplanar conformations of 1,3-dithio- and 1,3-dioxa-5,6-benzocycloheptene when groups having different dimensions substitute one or both of the hydrogen atoms at C 2. The results obtained show that bond lengths and bond angles are highly affected by the steric effect originating from the substituents. The chair conformation is the prevailing one in the 1,3-dithio-5,6-benzocycloheptene derivatives and the only possible when cumbersome substituents are attached at C 2, except in the di- t-butyl derivative. In the corresponding oxygenated molecules the chair form prevails when the steric effect is not relevant, otherwise the equilibrium shifts towards the twist conformation. The calculated barriers for the chair ↔ boat interconversion are in good agreement with the literature data concerning 1,3-dioxa-5,6-benzocycloheptene and its 2,2′-dimethyl derivative, whilst they are underestimated for the dithio derivatives. Barriers to the twist ↔ boat pseudorotation pathway are found only for some dithio derivatives. Ab initio 3G–21G ∗ calculations limited to the parent compounds were also performed.

Catalytic activities of nickel (II) complexes of a salen analog, [Ni(babp)], in epoxidation of olefins

A salen analog [Ni(babp)] (babp = 6,6′-bis (benzoylaminato)-2,2′-bipyridine (2—)) and its t-butyl derivative catalysed epoxidation of olefins in the presence of sodium hypochlorite as the oxidant. These complexes showed higher catalytic activity than [Ni (salen)] in epoxidation of an electron-deficient olefin, allyl chloride, yielding epichlorohydrin in 43% yield.

Fast Atom Bombardment Mass Spectra of Some N-α-(t-Butoxycarbonyl)-O-(diorganylphosphono)-L-serines and O-(Diorganylphosphono)seryl-Containing Dipeptides and Tripeptides

Positive and negative ion fast atom bombardment ( f.a.b .) mass spectrometry were found to be useful methods for the analysis and structural characterization of five Nα-(t- butoxycarbonyl )-O-( diorganylphosphono )-L- serines ( organyl = Ph, Et, Me, Bzl , But), especially in the case of the sensitive benzyl and t-butyl phosphono derivatives. Under positive ion operating conditions, high intensity pseudo-molecular ions were obtained in the f.a.b . mass spectra, and the fragmentation pathway of the phenyl, ethyl and methyl derivatives was established by parent/daughter linked scanning studies to involve (a) the two-step loss of the t- butoxycarbonyl group, (b) loss of the amino acid as the neutral fragment from the [MH]+, [MH-56]+, [MH-100]+ and [MH-146]+ ions by a four- centred β-elimination rearrangement, and (c) cleavage of the phosphono phenyl and ethyl groups from only the [(RO)2P(OH)2]+ and [NH=CHCH2PO3R2+H]+ fragments. Parent/daughter linked scanning studies of the benzyl derivative showed that the prominent fragmentation involved loss of the benzyl group as the tropylium ion and that the 'apparent' [MH-90]+ peak observed in its f.a.b. mass spectrum resulted from cleavage of the phosphono benzyl group in the matrix during the bombardment process. In the case of the t-butyl derivative, parent/daughter linked scanning studies showed that the prominent fragmentation involved successive 'in-flight' loss of the phosphono t-butyl groups as isobutene. Negative ion f.a.b. mass spectrometry of the five derivatives gave f.a.b. mass spectra which displayed distinct [M-H]- anions along with high intensity [M-H-R]- and [(RO)2PO2]- fragment anions, the f.a.b . mass spectrum of the t-butyl derivative containing an additional [M-H-But-But]- fragment anion. Parent/daughter linked scanning studies established that the majority of the observed fragment anions resulted from extensive fragmentation of the Boc -Ser(PO3R2)-OH derivatives in the matrix phase followed by sputtering of the resultant fragments into the gas phase. In addition, positive ion f.a.b . mass spectrometry was found to be useful for the analysis of a series of protected O-( diorganylphosphono ) seryl-containing dipeptides and tripeptides ( organyl = Ph, Et, Me, Bzl ). The obtained spectra showed that β-elimination fragmentation of the Ser(PO3R2) residue was more pronounced with the tripeptide series and indicated that there was increased sensitivity of the O-( diorganylphosphono ) seryl residue with replacement of the Boc group by an amino acyl residue at its N-terminus.

Electron Ionization and Chemical Ionization Mass Spectra of Some Nα-(t-Butoxycarbonyl)-O-(diorganylphosphono)-L-serines

N α -(t- Butoxycarbonyl )-O-( diorganylphosphono )L- serines underwent a complex fragmentation under both electron ionization and chemical ionization ( isobutane ) with the dominant pathway being a function of the phosphono organyl group (phenyl, ethyl, methyl, benzyl, t-butyl). In the case of the phenyl-, ethyl- and methyl-substituted derivatives, both electron ionization (15 eV) and chemical ionization mass spectra showed that β-eliminative loss of the seryl residue was the major pathway, and that the two-step loss of the t- butoxycarbonyl group from the [MH]+ ion was a inor pathway. In the case of the benzyl- and t-butyl-substituted derivatives, the poor mass spectra obtained under electron ionization conditions indicated that extensive thermal decomposition of the sensitive dibenzyl or di-t-butyl phosphate functionality occurred on the heated probe. Under the softer chemical ionization conditions, the mass spectrum of the benzyl-substituted derivative showed that loss of the phosphono benzyl group as the tropylium ion was the major fragmentation, and that both loss of the seryl residue by β-elimination and the cleavage of the t- butoxycarbonyl group were minor events. However, the poor chemical ionization spectrum obtained for the t-butyl derivative indicated that the di-t-butyl phosphate functionality was still sensitive to these milder conditions, with the compound undergoing decomposition on the heated probe.

Übergangsmetallkomplexe mit Schwefelliganden, LXXIII. Diastereospezifische Dichlormethylierung schwefelreicher [RuII(SRR′)(PPh3)′S4]-Komplexe (SRR′ = einzähniger Thioether- oder Thiol-Ligand; ′S4′2- = 1,2-Bis(2-mercaptophenylthio)ethan(2-)) / Transition Metal Complexes with Sulfur Ligands, LXXIII. Diastereospecific Dichloromethylation of Sulfur Rich [RuII(SRR′)(PPh3)′S4] Complexes (SRR′ = Monodentate Thioether or Thiol Ligand;′S4′2- = 1,2-Bis(2-mercaptophenylthio)ethane(2-))

Under exclusion of air the thioether and thiol complexes [Ru(SRR′)(PPh3)′S4′] (′S4′2- = 1,2-bis(2-mercaptophenylthio)ethane (2—)) easily react with CHCl3 yielding [Ru(Cl)(PPh3)(′S4′—CHCl2)] in which one thiolato atom of the ′S4′ ligand is diastereospecifically dichloromethylated. In the presence of air, however, [RuIII(Cl)(PPh3)′S4′] is formed. The molecular structures of [Ru(Cl)(PPh3)(′S4′-CHCl2)] · 2CHCl3 and [RuIII(Cl)(PPh3)′buS4′] have been determined by X-ray crystallography. ′buS4′2- (= 1,2-bis(3,5-di(t-butyl)-2-mercaptophenylthio)ethane(2-)) is the t-butyl derivative of the ′S4′ ligand. Reasons for observed diastereospecifity of alkylation are discussed.

Cyclopentadienyl-ruthenium and -osmium chemistry Part XXXIV. Reactions of 1-alkynes with σ-vinyl-ruthenium complexes. X-ray structures of Ruη 3-CH(CO 2Me)C(CO 2Me)CCHPh(PPh 3)(η-C 5H 5) and Ru(η-C 5H 5)η 5-C 3(CO 2Me) 3CHC tBuCH(CO 2Me)

Reactions between HC 2R (R = Ph, tBu) and the chelate vinyl ester complex RuC(CO 2Me)CHC(O )OMe(PPh 3)(η-C 5H 5) have given η 3-allyl derivatives Ruη 3-CH(CO 2Me)C(CO 2Me)CCHR(PPh 3)(η-C 5H 5), as shown by an X-ray structure of the phenyl derivative. Similarly, the reaction between HC 2Ph and RuC(OMe)CH(CO 2Me)(PPh 3) 2(η-C 5H 5) gave Ruη 3-CH(CO 2Me)C(OMe)CCHPh(PPh 3)(η-C 5H 5). These reactions probably proceed via displacement of the ester carbonyl group or PPh 3 by the 1-alkyne, which isomerises to the corresponding vinylidene before a formal insertion into the Ru-C( sp 2) bond. Complexes containing cyclic adducts of the 1-alkyne and the butadienyl ligand, namely Ru(η-C 5H 5)η 5- C 3(CO 2Me) 3CHCRC H(CO 2Me), were obtained from Ru C(CO 2Me)C(CO 2Me)C(CO 2Me)CH(CO 2Me)(PPh 3)(η-C 5H 5) and HC 2R (R = Ph, tBu), as shown by an X-ray structure of the t-butyl derivative. A small amount of an η 5-vinylcyclohexadienyl complex was also obtained from the reaction with HC 2Ph. In these reactions, the 1-alkyne does not isomerise, probably for steric reasons; the first step may involve replacement of PPh 3 by the alkyne, rather than formation of an η 1-butadienyl complex.

ChemInform Abstract: Molecular Mechanics Study of Hindered Phenols Used as Antioxidants

The influence of 2,6-substituents on the properties and reactions of hindered phenols (1) and peroxides (2) has been studied by computer-assisted molecular modelling and molecular mechanics and the results of the calculations have been compared with our experimental observations. The minimum-energy configurations of the 2,6-disubstituted peroxides, (R2C6H3O)2(R = Me, Et, Pri, But), were evaluated in order to assess the repulsion across the peroxy group between the substituents in the phenyl rings, and hence the feasibility of the dimerisation of the corresponding phenoxy radicals.Molecular mechanics calculations were performed with the MM2 program of Allinger with a variety of forcefield parameters of the C—O—O—C linkage. In the minimised structure for bis(2,6-dimethylphenyl)peroxide there were no steric repulsions greater than 0.1 kcal mol–1 between methyl groups regardless of the values of the C(ar)—C(ar)—O—O and C(ar)—O—O—C(ar) torsion angles. However, the steric energy of the di-ethyl, -isopropyl, and -isobutyl compounds was dependent upon the values of these torsion angles with preferred C(ar)—C(ar)—O—O angles closer to 90 than 180 °. The minimum energies increased in the order Me < Et < Pri But. The steric energy of the t-butyl derivative was much the highest (47 kcal mol–1 compared with less than 12 kcal mol–1 for the other three). Owing to the steric effect of the t-butyl groups, the t-butyl peroxide is unstable and the HO group of the corresponding bis(t-butyl)phenol is protected and hence unreactive. These conclusions are consistent with experimental results which indicate the absence of hydrogen bonding and the lack of reactivity of the HO group of 2,6-di(t-butyl)phenol.

Molecular mechanics study of hindered phenols used as antioxidants

The influence of 2,6-substituents on the properties and reactions of hindered phenols (1) and peroxides (2) has been studied by computer-assisted molecular modelling and molecular mechanics and the results of the calculations have been compared with our experimental observations. The minimum-energy configurations of the 2,6-disubstituted peroxides, (R2C6H3O)2(R = Me, Et, Pri, But), were evaluated in order to assess the repulsion across the peroxy group between the substituents in the phenyl rings, and hence the feasibility of the dimerisation of the corresponding phenoxy radicals.Molecular mechanics calculations were performed with the MM2 program of Allinger with a variety of forcefield parameters of the C—O—O—C linkage. In the minimised structure for bis(2,6-dimethylphenyl)peroxide there were no steric repulsions greater than 0.1 kcal mol–1 between methyl groups regardless of the values of the C(ar)—C(ar)—O—O and C(ar)—O—O—C(ar) torsion angles. However, the steric energy of the di-ethyl, -isopropyl, and -isobutyl compounds was dependent upon the values of these torsion angles with preferred C(ar)—C(ar)—O—O angles closer to 90 than 180 °. The minimum energies increased in the order Me < Et < Pri But. The steric energy of the t-butyl derivative was much the highest (47 kcal mol–1 compared with less than 12 kcal mol–1 for the other three). Owing to the steric effect of the t-butyl groups, the t-butyl peroxide is unstable and the HO group of the corresponding bis(t-butyl)phenol is protected and hence unreactive. These conclusions are consistent with experimental results which indicate the absence of hydrogen bonding and the lack of reactivity of the HO group of 2,6-di(t-butyl)phenol.

Radical cations of nitroso derivatives. A radiation-chemical and electron spin resonance study

Exposure of dilute solutions containing nitrosobenzene in trichlorofluoromethane to 60Co γ-rays at 77 K gave the corresponding radical cation, characterised by e.s.r. spectroscopy. The results confirm the interpretation of liquid-phase data assigned to this cation, which showed that loss is from an in-plane σ-orbital localised on nitrogen and oxygen, rather than from the aromatic π-system. However, solutions containing the t-butyl derivative in equilibrium with its dimer,(Me3CNO)2, gave primarily the dimer cation, (Me3CNO)+2, with possible traces of the monomer cation. The e.s.r. data for the latter resemble those for the nitrosobenzene cation, whereas results for the dimer cation suggest that loss is from a π-type orbital with very low spin density on the two equivalent nitrogen atoms.

Übergangsmetallkomplexe mit Schwefelliganden: XXX. Struktur, stereoisomerie und reaktivität von eisen-, molybdän- und ruthenium-komplexen mit den fünfzähnigen thioether-thiolat-liganden dpttd2 = 2,3,11,12-dibenzo-1,4,7,10,13-pentathiatridecan(−2) und tbu4-dpttd2− = 14,16,18,20-tetra-t-butyl-2,3,11,12-dibenzo-1,4,7,10,13-pentathiatridecan(−2)

meso-[Fe(CO)(dpttd)] (dpttd2− = 2,3,11,12-dibenzo-1,4,7,10,13-pentathiatridecane(−2)) can be isolated by fractional crystallization from a mixture of diastereomers of [Fe(CO)(dpttd)] and was characterized by X-ray structure analysis. The Fe center in meso-[Fe(CO)(dpttd)] is pseudo-octahedrally coordinated by one C and five S atoms and contains a mirror plane. The t-butyl derivative of dpttd-H2, the sterically demanding pentadentate thioether thiolate [tbu4-dpttd]2− (= 14,16,18,20-tetra-t-butyl-2,3,11,12-dibenzo-1,4,7,10,13-pentathiatridecane(−2)) coordinates to Fe, Ru and Mo centers yielding mixtures of diastereomeric complexes. Thus FeCl2·4H2O reacts with Na2[tbu4-dpttd)] to give diastereomers of [Fe(tbu4-dpttd)], which coordinate CO to give three diastereomers of [Fe(CO)(tbu4-dpttd)], two of which could be separated. One of these was unambiguously identified by 1H NMR spectroscopy to be meso-[Fe(CO)(tbu4-dpttd)]. meso-[Fe(CO)(tbu4-dpttd)] reacts with NO+ retaining its configuration to yield meso-[Fe(NO)(tbu4-dpttd)]+; a reaction mechanism via thionitrosylation of a thiolate S atom of the tbu4-dpttd2− ligand is proposed. The reaction of [MoCl4(THF)2] with tbu4-dpttd-H2 and H2O yields a mixture of diastereomers of [MoO(tbu4-dpttd)], from which meso-[MoO(tbu4-dpttd)] is isolated by fractional crystallization. Reaction of RuCl3(NO)·χH2O and [RuCl3(PhSCH3)3] with tbu4-dpttd2− yields mixtures of diastereomers of [Ru(NO)(tbu4-dpttd)]+ and [Ru(Cl)(PhSCH3)(tbu4-dpttd)]2, respectively; the latter is reduced by Zn to give [Ru(PhSCH3)(tbu4-dpttd)].