Showing papers in "Australian Journal of Chemistry in 1981"
TL;DR: Arsenobetaine has been isolated from the tail muscle of the western rock lobster (Panulirus cygnus George) and from the flesh of the dusky shark (Carcharhinus obscurus Le Sueur), both of which are commercially important seafoods as mentioned in this paper.
Abstract: Arsenobetaine has been isolated from the tail muscle of the western rock lobster (Panulirus cygnus George) and from the flesh of the dusky shark (Carcharhinus obscurus Le Sueur), both of which are commercially important seafoods. Trigonelline has also been isolated from the lobster and both arsenobetaine and trigonelline have been isolated from human urine obtained after ingestion of cooked rock lobster. The crystal structures of the monohydrates of arsenobetaine and trigonelline have been determined and a simple synthesis of arsenobetaine has been developed.
157 citations
TL;DR: The structure of a tetragonal crystal of the title compound was determined by X-ray diffraction as mentioned in this paper, and the space group was found to be P4/nmm with a 6.202/2 and c 7.410(1) A and Z 2.567(5) A, indicating the presence of the cation VO3+.
Abstract: The structure of a tetragonal crystal of the title compound was determined by X-ray diffraction. The space group was found to be P4/nmm with a 6.202(2) and c 7.410(1) A and Z 2. The structure consists of infinite sheets of distorted VO6 octahedra and PO4 tetrahedra linked by shared oxygen atoms. Shared water molecules link these sheets together. A short V-O(4) bond, 1.567(5) A, indicates the presence of the cation VO3+.
141 citations
TL;DR: In this article, spectra for aqueous solutions of the anti-cancer drug cis-diamminedichloroplatinum(II) and its hydrolysis and oligomerization products are reported.
Abstract: 195Pt and 15N n.m.r, spectra for aqueous solutions of the anti-cancer drug cis-diamminedichloroplatinum(II) and its hydrolysis and oligomerization products are reported. In the blood substituteHanks medium, conversion of cis-[Pt(15NH3)2(H20)2](NO3)2 into cis[PtCl2(15NH3)2], cis-[PtCl(H20)(15NH3)2]+,[Pt(15NH3)2OH]33+ and [Pt(15NH3)2OH]22+ has been observed, the reaction taking several hours at 30oC. In 0.15 M sodium chloride, both [Pt(NH3)2OH]33+ and[Pt(NH3)2OH]22+ are converted overnight into cis-[PtCl(H2O)(NH3)2]+. The infrared bands at 546 and 522 cm-1 in [Pt(NH3)2OH]2SO4 and at 520 cm-1 in [Pt(NH3)2OH]2(SO4)3 have been reassigned to Pt-N modes.
99 citations
TL;DR: In this article, it was shown that a layer of sulfur forms on corroding chalcopyrite, but this is not the species which slows transport of ions and transfer of electrons.
Abstract: Electrochemical aspects of semiconductors are used to interpret well established observations on the kinetics of leaching of chalcopyrite. The oxidation of this n-type semiconductor is dominated by a surface film which is thermally unstable and breaks down in CS2, acetone or acidified water, or under dry nitrogen, over comparable time periods. The film is thought to be a semiconductor metal-deficient polysulfide which slows transport of Cu+ and Fe2+ products, slows electron transfer to oxidants such as Fe3+ and Cu2+, and dramatically slows supply of holes and thus electron transfer from reduced species such as Fe2+ on corroding chalcopyrite. Thus the Fe3+/Fe2+ couple (especially as sulfate) is much less reversible on corroding chalcopyrite than on pyrite or platinum. The couples Cu2+/Cu+,I3-/I- and Fe(CN)63-/Fe(CN)64- are more reversible than Fe3+ /Fe2+ but all couples are much less reversible on chalcopyrite than on pyrite.
A layer of sulfur forms on corroding chalcopyrite, but this is not the species which slows transport of ions and transfer of electrons. A mixture of Fe3+/Cu2+ chlorides is one of the more effective oxidants for CuFeS2 because of relatively fast electron transfer from corroding chalcopyrite to Cu2+ and oxidation of Cu+ by Fe3+. Catalysis by iodine and by inclusion of Ag2S or FeS2 in natural chalcopyrite is explained by the electrochemical model.
92 citations
TL;DR: In this article, seven novel metabolites, each originating from four bromotyrosine units, have been isolated from the sponge Ianthella basta, and they showed potent in vitro antimicrobial activity against Gram-positive organisms.
Abstract: Seven novel metabolites, each originating from four bromotyrosine units, have been isolated from the sponge Ianthella basta. Bastadin-1 (2), bastadin-2(3) and bastadin-3(4) are derived from a single phenol oxidative coupling whilst the macrocyclic compounds bastadin-4(5), bastadin-5(6), bastadin-6(8) and bastadin-7(7) are formed by two phenol oxidative coupling reactions. Compounds (2)-(8) showed potent in vitro antimicrobial activity against Gram-positive organisms.
82 citations
TL;DR: In this paper, a radial flow apparatus was used for streaming potential measurements on crushed and sheet muscovite mica and showed that both aluminium and silicon leach out of the mica.
Abstract: Electrophoresis and streaming potential data are reported for crushed and sheet muscovite mica respectively. For streaming potential measurements a newly designed radial flow apparatus was used. Measurements on crushed mica show that both aluminium and silicon leach out of the mica. Leached aluminium and silicon may readsorb to confer increased positive and negative charge respectively on the mica. Electrophoresis data indicate that leaching of aluminium occurs more rapidly than of silicon. Aging experiments on sheet mica show leaching effects to be much slower than on crushed mica. Streaming potential measurements on freshly cleaved mica sheets showed that (i) the zeta- potential depended strongly on electrolyte (KCl) concentration; (ii) the zeta-potential was relatively independent of pH and (iii) monovalent cations were adsorbed in the sequence H+ > Cs+ > K+ > Na+ > Li+, whilst Ca2+ adsorbed more strongly than K+. It is proposed that the structure of the electrical double layer at the mica/electrolyte interface results from the distribution of all ions between the diffuse layer, the Stern plane (hydrated) and more critically the lattice holes of the silica-alumina basal plane.
61 citations
TL;DR: The light-induced formation of hydrogen in the system H2O-Ru(bpy)32+-mv2+-edta-Pt (mv, inethylviologen) is accompanied by the hydrogenation of mv 2+ to give the 1-methyl-4-(1'-methylpiperidin-4'-yl)pyridinium cation (1) as discussed by the authors.
Abstract: The light-induced formation of hydrogen in the system H2O-Ru(bpy)32+-mv2+-edta-Pt (mv, inethylviologen) is accompanied by the hydrogenation of mv2+ to give the 1-methyl-4-(1'-methylpiperidin-4'-yl)pyridinium cation (1). The production of hydrogen is decreased by factors that favour the formation of this cation. The extent of hydrogenation depends on the pH of the mixture, the amount and type of catalyst present, and the partial pressure of hydrogen during irradiation.
60 citations
TL;DR: In this article, the crystal structure of tetraammine-2, 4-diamme, cobalt-III dithionate dihydrate has been determined by X-ray structure analysis.
Abstract: The crystal structure of tetraammine{(±)-pentane-2, 4-diamme)cobalt(III) dithionate dihydrate [Co{(±)-ptn)(NH3)4] (S2O6)1·5, 2H2O has been determined by X-ray structure analysis. The crystals are triclinic with the space group PĪ, with a 11·43, b 11·65, c 7·78 A, α 100·48°, s 105·95°, and y 75·95°. The structure has been refined by least-squares methods with anisotropic temperature factors to an R value of 0-043 for 2654 reflections. The six-membered diamine chelate ring has a skew-boat conformation in which the two methyl groups are in equatorial orientations. A strainenergy-minimization calculation for the complex reveals an energy difference of 8·3 kJ mol-1 between the preferred skew-boat conformation and the chair conformation. The calculated minimum-energy geometry for the skew-boat conformation is in good agreement with the observed structure for the chelate ring in the dithionate salt. The 1H n.m.r. spectra of this complex and other complexes of the chiral isomer of pentane-2, 4-diamine are discussed in terms of the observed structures and the conformational analysis.
58 citations
TL;DR: In this paper, selective methylation of some compounds containing both SH and NH groups was performed to give first the S-methyl and subsequently the S,N-dimethyl derivatives.
Abstract: Methylations of heterocyclic systems, such as benzimidazole, naphth[2,3-c]imidazole, imidazo[4,5-c]-pyridine, purine, pyridine, pyrimidine, pyridazine and s-triazolo[4,3-b]pyridazine, which bore SH, NH and/or OH groups, were carried out with dimethylformamide dimethyl acetal to give the corresponding S-, N- and/or O-methyl derivatives in high yields. Selective methylation of some compounds containing both SH and NH groups took place to give first the S-methyl and subsequently the S,N-dimethyl derivatives. No side reactions, such as C-methylation, were observed.
49 citations
TL;DR: X-ray crystallographic analysis shows that endiandric acid and derived lactone have the respective structures 2-(6'- phenyltetracyclo[5,4,2,03,13,010,12]trideca-4',8'-dien-11'-yl)acetic acid and 12-phenyl-3-oxapentacyclos[7,5,2.02,6,07,15,013,16]hexadecan-4-one] as discussed by the authors.
Abstract: X-ray crystallographic analysis shows that endiandric acid and a derived lactone have the respective structures 2-(6'- phenyltetracyclo[5,4,2,03,13,010,12]trideca-4',8'-dien-11'-yl)acetic acid and 12-phenyl-3-oxapentacyclo[7,5,2,02,6,07,15,013,16]hexadecan-4-one.
46 citations
TL;DR: In this article, the dependence on composition of the polarity of H2O+MeCN mixtures has been determined from measurements of the empirical solvent polarity parameter ET, and the variation of ET with composition is interpreted in terms of the Naberukhin-Rogov structural model for H 2O+nonelectrolyte mixtures.
Abstract: The dependence on composition of the polarity of H2O+MeCN mixtures has been determined from measurements of the empirical solvent polarity parameter ET. ET has been found to vary with composition in a similar fashion to that which has been reported previously for most other H2O+non-electrolyte mixtures for which ET data are available. The variation of ET with composition is interpreted in terms of the Naberukhin-Rogov structural model for H2O+nonelectrolyte mixtures.
TL;DR: In this article, a ring-opening reaction of 2,5-dihydrothiophen 1-oxide and 2,1,3-dienylsulfenate is described.
Abstract: Under certain conditions the anions from 2,5-dihydrothiophen 1-oxide and 2,5-dihydrothiophen 1,l-dioxide undergo ring-opening reactions and the resulting buta-1,3-dienylsulfenate and buta-1,3- dienylsulfinate ions respectively may be alkylated. The anion from 2,5-dihydrothiophen also rearranges to the buta-1,3-dienylthiolate ion which may be alkylated, but the overall reaction is incomplete and pure products cannot be isolated; instead 1-(alkylthio)buta-1,3-dienes may conveniently be prepared by base-catalysed ring-opening reactions of 1-alkyl-2,5-dihydrothiophenium salts. The 1-(alkylthio), 1-(alkylsulfinyl)- and 1-(alkylsulfonyl)buta-1,3-dienes isolated from the above reactions are very unstable, and rapidly polymerize on standing at ambient temperatures.
TL;DR: In this article, the empirical solvent polarity parameters ET and Z have been determined as a function of composition for the binary solvent systems 1, 2-dibromoethane + 1,2-Dibromopropane, acetone + chloroform and dichloromethane.
Abstract: Values of the empirical solvent polarity parameters ET and Z have been determined as a function of composition for the binary solvent systems 1,2-dibromoethane + 1,2-dibromopropane, acetone + chloroform, acetone + ethanol, ethanol + chloroform and acetone + dichloromethane. For the 1,2-dibromoethane + 1,2-dibromopropane system both ET and Z are accurately linear (i.e. additive) functions of composition. For the other systems both parameters vary with composition in a strongly non-additive manner, and the deviations from additivity are interpreted in terms of intermolecular interactions. For these systems, in general ET and Z are not highly correlated, and neither parameter is highly correlated with other macroscopic properties or parameters derived from them.
TL;DR: The crystal structures of the trans complexes bis(ethane-1,2-diamine)dinitronickel(II) (1), bis[N,N-dimethyl (ethane)-1, 2-diarnine)]dinitritonickel(III) (2) and bis[ N,N'-dimethyl(ethANE-1-2-dimine)-dinitronized monohydrate (3) are described in this paper, where the steric requirements of amine substituents are explained.
Abstract: The crystal structures of the trans complexes bis(ethane-1,2-diamine)dinitronickel(II) (1), bis[N,N-dimethyl(ethane-1,2-diarnine)]dinitritonickel(II) (2) and bis[N,N'-dimethyl(ethane-1,2-diamine)]dinitronickel(II) monohydrate (3) are described, (1) and (2) being redeterminations of previously reported structures. The complexes formed by the substituted amines have significantly different geometries, both in the manner of coordination of the nitrite ligands, and in the conformations adopted by the diamine chelate rings. These differences can be explained in terms of the particular steric requirements of the amine substituents. The changes in nitrite geometry which occur upon coordination, and the spectroscopic properties of the complexes are discussed.
TL;DR: Experimental dipole moments, molar Kerr constants and molar Cotton-Mouton constants at 298 K and 633 nm are reported for pyrrole, pyrazole, imidazole and their N-methyl derivatives as solutes in dioxan as mentioned in this paper.
Abstract: Experimental dipole moments, molar Kerr constants and molar Cotton-Mouton constants at 298 K and 633 nm are reported for pyrrole, pyrazole, imidazole and their N-methyl derivatives as solutes in dioxan. Analysis of the Kerr-effect data yields the effective polarizability anisotropies which are used to evaluate the molecular magnetic anisotropies from the Cotton-Mouton constants. The magnetic criterion of aromaticity is applied by estimating for each molecule the non-local contribution to the out-of-plane component of the magnetizability and the magnetic anisotropy. Electron delocalization in these molecules is significantly less than that exhibited by benzene: pyrrole and N-methylpyrrole, c. 70%; pyrazole and N-methylpyrazole, c. 65%; imidazole and N-methyl-imidazole, c. 60%. Approximately one-third of the observed magnetic anisotropy arises from localized contributions.
TL;DR: A number of bis(phenylethynyl)-substituted anthracenes and naphthacenes have been synthesized and their suitability as fluorescent additives for peroxyoxalate chemiluminescence evaluated as mentioned in this paper.
Abstract: A number of bis(phenylethynyl)-substituted anthracenes and naphthacenes have been synthesized and their suitability as fluorescent additives for peroxyoxalate chemiluminescence evaluated. Fluorescence and chemiluminescence emission data for all compounds are presented. Both 2-chloro- and 6-chloro-5,12-bis(phenylethynyl)naphthacene provide effective scarlet chemiluminescence with the peroxyoxalate system (λmax 609 and 614 nm respectively). Although solutions of both compounds decolorize slowly in the presence of air and light, when used in concentrations of 1-5 × 10-3M they allow efficient chemiluminescence for greater than 5 h.
TL;DR: Extraction of Pimelea simplex F. Muell and P. decora Domin has yielded flavone and several methoxyflavones of unusual oxygenation patterns.
Abstract: Extraction of Pimelea simplex F. Muell. and P. decora Domin. has yielded flavone and several methoxyflavones of unusual oxygenation patterns: 2'-methoxyflavone and 7-methoxyflavone from P. simplex, and 3'-methoxyflavone, 6-methoxyflavone, 3',6-dimethoxyflavone and 2',3',6- trimethoxyflavonefrom P. decora. The structures of the substances were confirmed by synthesis from the corresponding chalcones. The 13C n.m.r, spectral data of the flavones and chalcones are tabulated.
TL;DR: In this article, a series of O,O-dialkyldithiophosphate (dtp) and dialkylditiocarbamate (dtc) complexes of cadmium and mercury in dichloromethane solution were studied.
Abstract: Phosphorus-31, cadmium-113 and mercury-199 n.m.r. spectra have been recorded for a series of O,O-dialkyldithiophosphate (dtp) and dialkyldithiocarbamate (dtc) complexes of cadmium and mercury in dichloromethane solution. Both types of ligand are labile on the n.m.r. time scale at room temperature, although the exchange of dtc ligands can be slowed at low temperatures. .The complexes interact with tributylphosphine and tricyclohexylphosphine (pcy), but at room temperature the phosphines are also labile. At low temperatures, however, the phosphine exchange becomes slow on the n.m.r. time scale to allow identification of the adducts except for Cd(dtc)2 adducts with PBu3 which are still labile at -110°C. All the data indicate that cadmium has a lower affinity for phosphine than mercury and that dtc ligands are more strongly bound to the metals than dtp ligands.
TL;DR: The dichloromethane-soluble secondary metabolites of four Cystophora species and two new acyl phloroglucinols isolated from C. monilifera have been established by a combination of spectral and chemical methods.
Abstract: The dichloromethane-soluble secondary metabolites of four Cystophora species, C. monilifera, C. congesta, C. expansa and C. scalaris, are described. The structures of two new acyl phloroglucinols isolated from C. monilifera have been established by a combination of spectral and chemical methods.
TL;DR: In this article, it was shown that reaction of HO-(or MeO-) with silane should proceed through a stable trigonal bipyramidal adduct, and that C3H3- may either react as HC≡C-CH2- or -HC=C=CH2.
Abstract: Ab initio LCAO-MO-SCF calculations suggest that reaction of HO-(or MeO-) with silane should proceed through a stable trigonal bipyramidal adduct. Reaction of alkoxide anions with a variety of alkylsilanes in an i.c.r. spectrometer leads to (i) nucleophilic displacement reactions, (ii) stable adducts, (iii) decomposing adducts which collapse to tetrahedral anions by elimination of a neutral molecule, and (iv) proton abstraction reactions. The nucleophilic displacement reaction between MeO- and Me3SiR has been used to produce a variety of R- species, including the allyl, propargyl and benzyl anions. The reactions of these ions with methyl nitrite have been used to show that (i) the benzyl anion does not undergo benzylic hydrogen/phenyl hydrogen scrambling prior to reaction, (ii) the allyl anion reacts as a symmetrical species, and (iii) that hydrogen scrambling does not occur in the propargyl anion, and that C3H3- may either react as HC≡C-CH2- or -HC=C=CH2.
TL;DR: In this paper, two monocyclic sesquiterpenes have been isolated from the green alga Caulerpa flexilis (Lamx) var. muelleri (Sond.) (Wom.).
Abstract: Two new monocyclic sesquiterpenes have been isolated from the green alga Caulerpa flexilis (Lamx) var. muelleri (Sond.) (Wom.).
TL;DR: In this paper, the lithiation of methoxy-and methylenedioxy-bemyl alcohols is described, and subsequent reactions with ethyl chloroformate and carbon dioxide to form phthalides have been investigated, and compared with metallation-carboxylation of alternative substrates.
Abstract: The lithiation of methoxy- and methylenedioxy-bemyl alcohols is described; subsequent reactions with ethyl chloroformate and carbon dioxide to form phthalides have been investigated, and are compared with metallation-carboxylation of alternative substrates. The preparation of phthalideisoquinoline analogues by this method proceeds only in low yields due to the acidity of the benzylic position in the benzylisoquinoline precursor.
TL;DR: In the presence of NH4PF6, a tri-alkyloxonium salts alkylate the cyano complex affording [Ru(CNR)(PPh3)2(η-C5H5)]PF6 as mentioned in this paper.
Abstract: Reactions between isonitriles and RuCl(PPh3)2(η-C5H5) have given RuCl(CNR)(PPh3)(η-C5H5)(R = But, c-C6H11, CH2S02C6H4Me-p or C6H40Me-p) and RUCl(CNBut)2(η-C5H5); in the presence of NH4PF6, cationic complexes [RU(CNR)(PPh3)2(η-C5H5)]PF6 (R = But, c-C6H11 or CH2SO2C6H4Me-p) and [RU(CNBut)2(PP~h3)(η-C5H5)]PF6 were obtained. Protonation of Ru(CN)- (PPh3)2(η-C5H5) gives the hydrogen isocyanide derivative [Ru(CNH)(PPh3)2(η-C5H5)]PF6; tri- alkyloxonium salts alkylate the cyano complex affording [Ru(CNR)(PPh3)2(η-C5H5)]PF6 (R = Me or Et).
TL;DR: In this paper, a Diels-Alder addition of the silyloxy dienes (10 and 11) to simpler quinones was used to synthesize the insect anthraquinones kermesic acid (3) and laccaic acid D (2).
Abstract: The insect anthraquinones kermesic acid (3) and laccaic acid D (2) have been synthesized efficiently, as have the plant anthraquinones aloesaponarin-I (4) and -11 (33). The syntheses were based on regiospecific Diels-Alder addition of the silyloxy dienes (10) and (11) to simpler quinones. Regiospecificity was controlled by 2(3)-chloro groups in the dienophiles or, for addition to certain naphthoquinones, by a hydroxy group peri to carbonyl.
TL;DR: In this article, the existence of a first-order phase transition which occurs at a characteristic distance of separation between two adsorbing walls is discussed. And the thermodynamic properties of this new transition are discussed.
Abstract: In a recent paper we have reported the existence of a first-order phase transition which occurs at a characteristic distance of separation between two adsorbing walls. In this paper we discuss some of the thermodynamic properties of this new transition.
TL;DR: In this paper, the coupling constants for protons on the cyclohexene rings are used to show that the first two adducts probably have half-chair conformations, while the last has boat conformations.
Abstract: 1-Benzyl-3-vinylindole gives stable adducts resulting from [2+4] cycloadditions with 1,4-benzo-quinone, 1,4-naphthoquinone, N- phenylmaleimide and maleic anhydride. Vicinal 1H n.m.r. coupling constants for protons on the cyclohexene rings are used to show that the first two adducts probably have half-chair conformations, while the last have boat conformations. Non-equivalence of the benzyl methylene protons of the benzoquinone adduct has been shown to display a surprising temperature dependence. The adduct of the vinylindole and ethenetetracarbonitrile is shown to be a cyclobutane resulting from a [2+2] cycloaddition.
TL;DR: In this paper, the number of phosphines coordinated to the mercury depends upon the steric requirements of the phosphine and the nature of the anion A. Chemical shifts and coupling constant data imply coordination of all the anions, except perchlorate, to mercury.
Abstract: Phosphorus-31 and mercury-199 n.m.r. techniques have been used to investigate the formation of mercury(II) complexes HgA2(phos)1-4 [where A = ClO4-, NO3-, CF3COO-, CH3COO-, SCN-, CN-, Cl-, Br-, I- and phos = P(4-ClC6H4)3, P(4-CH3OC6H4)3, P(2-CH3OC6H4)3, P(4-CH3C6H4)3, P(2-CH3C6H4)3, P(3-CH3CH6H4)3, PBu3, P(C6H11)3 and PPh3] in dichloromethane solution. The number of phosphines coordinated to the mercury depends upon the steric requirements of the phosphine and the nature of the anion A. Phosphorus-31 and mercury-199 chemical shifts and coupling constant data imply coordination of all the anions, except perchlorate, to mercury. Mercury chemical shifts are discussed in terms of electron density at the metal and coordination number of the metal.
TL;DR: In this article, the soft coral Sinularia facile afforded two cembranoid diterpenes whose structures and absolute configurations have been determined as (1R,4R,2E,7E,11E)-cembra-2,7,11-trien-4-ol (1) and ( 1R,3S,4S, 7E, 11E)-3,4-epoxycembras-7, 11,15-triene (2).
Abstract: Extraction of the soft coral Sinularia facile afforded two cembranoid diterpenes whose structures and absolute configurations have been determined as (1R,4R,2E,7E,11E)-cembra-2,7,11-trien-4-ol (1) and (1R,3S,4S,7E,11E)-3,4-epoxycembra-7,11,15-triene (2).
TL;DR: In this article, the enantiomer of calamenene isolated from the gorgonian Subergorgia hicksoni has been shown to be the same as (1R, 4S)-(-)-8-Methoxycalamenene.
Abstract: (1R,4S)-(-)-Calamenene has been synthesized from dihydroxyserrulatic acid of known absolute configuration. (1R,4S)-(-)-8-Methoxycalamenene is shown to be the enantiomer of a calamenene isolated from the gorgonian Subergorgia hicksoni
TL;DR: In this paper, a qualitative study of the solvent dependence of selenium-77 chemical shifts is reported, where it is shown that the ditertiary phosphine Ph2PCH2PPh2 reacts with the SeCN- ion to give predominantly the monoselenated derivative PH2P(Se)CH2pPh2, but with the diphosphine Ph 2P(CH2)2PPH2 the diselenated derivative is obtained.
Abstract: Hydrogen-1,carbon-13,phosphorus-31 and selenium-77 n.m.r. studies have been carried out on some organophosphine selenides. The n.m.r. studies show that the ditertiary phosphine Ph2PCH2PPh2 reacts with the SeCN- ion to give predominantly the monoselenated derivative Ph2P(Se)CH2PPh2, but with the diphosphine Ph2P(CH2)2PPh2 the diselenated derivative is obtained. A qualitative study of the solvent dependence of selenium-77 chemical shifts is reported.