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PubMed2005

Brain-derived growth factor and glial cell line-derived growth factor use distinct intracellular signaling pathways to protect PD cybrids from H2O2-induced neuronal death.

The cause of idiopathic PD is obscure, and most cases are sporadic. Oxidative stress and deficiency of various neurotrophic factors (NTFs) could be factors triggering neurodegeneration in the substantia nigra (SN). Cytoplasmic hybrid cells (cybrids) made from mitochondrial DNA of idiopathic PD subjects have reduced glutathione (GSH) levels and increased vulnerability to H2O2. Brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) rescue PD cybrids from H2O2-induced cell death. GDNF mediated effects require Src kinase and phosphatidylinositol 3-kinase (PI3K)/Akt activation. Inhibiting either PI3K/Akt or ERK pathways blocks the effects of BDNF. Inhibiting p38MAPK and c-Jun N-terminal kinase (JNK) pathways enhances the neuroprotective effects of both NTFs. These results demonstrate that expression of PD mitochondrial genes in cybrids increases vulnerability to oxidative stress that is ameliorated by both BDNF and GDNF, which utilize distinct signaling cascades to increase intracellular GSH and enhance survival-promoting cell signaling.

Aged↗
PubMed2005

Theoretical and experimental study on formation and adsorption of enolic species on Ag-Pd/Al2O3 catalyst.

The formation and adsorption of enolic species on a palladium promoted Ag/Al2O3 catalyst (denoted Ag-Pd/Al2O3) during the selective catalytic reduction (SCR) of NOx by C3H6 has been studied by means of DRIFTS and density functional calculations. The structure of the enolic species adsorbed on Ag-Pd/Al2O3 catalyst has been established based on the in situ DRIFTS spectra and simulated results. The reaction mechanism from C3H6 to enolic species on Ag-Pd/Al2O3 catalyst was proposed and the hypothesis about the Pd promotion was discussed.

Aluminum Oxide↗
PubMed2004

Dopamine agonists and sleepiness in PD: review of the literature and personal findings.

BACKGROUND AND PURPOSE: This study is aimed at evaluating daytime sleepiness in a series of Parkinson's disease (PD) patients chronically treated with dopamine agonists (DAs) alone or in combination with L-Dopa. PATIENTS AND METHODS: A preliminary series of 22 non-demented, adult PD patients (mean age 68.9, 13 men and 9 women) were evaluated by means of structured sleep interview, Epworth sleepiness scale (ESS) and 24-h ambulatory polysomnography (A-PSG). RESULTS: Sleep attacks (SAs) were reported by 32% of the patients, in three of them (43%) after DA treatment was initiated (alone or in addition to L-Dopa). In two patients, both with chronic use of ropinirole, we documented NREM SAs during a continuous ambulatory polysomnography (A-PSG) performed in the patients' real-life settings. The subjects experiencing SAs showed a higher degree of daytime sleep propensity than those without SA, having higher ESS scores and a higher proportion of microsleeps and intentional naps on A-PSG. Interestingly, we found that nocturnal total sleep time is higher in PD patients with SAs than in the others. CONCLUSIONS: All in all, our data indicate that SAs are an extreme manifestation of increased daytime sleepiness. The occurrence of SAs in our series of PD patients is unlikely to depend simply on the demands of homeostatic mechanisms.

Aged↗
PubMed1997

Dopamine D2 receptors play a role in the (-)-apomorphine-like discriminative stimulus effects of (+)-PD 128907.

The discriminative stimulus effects of the dopamine D3 receptor-preferring agonist, S(+)-(4aR,10bR)-3,4,4a,10b-tetrahydro-4-propyl -2H, 5H-[1]benzopyrano-[4,3-b]-1,4-oxazin-9-ol ((+)-PD 128907), were examined in rats trained to discriminate (-)-apomorphine (0.16 m/kg) from saline in a two-lever, fixed ratio 10 drug-discrimination paradigm. Both (-)-apomorphine and (+)-PD 128907 produced dose-related (-)-apomorphine-lever selection, with full substitution observed at 0.16 mg/kg, i.p. (ca. 0.5 mumol/kg). Drug-appropriate responding produced by either (-)-apomorphine or (+)-PD 128907 was antagonized by the putative dopamine D3 receptor antagonists, (1S,2R)-cis-5-methoxy-1-methyl-2-(n-propylamino)tetralin) ((+)-AJ76) and cis-(+)-5-methoxy-1-methyl-2-(di-n-propylamino)tetralin ((+)-UH 232), as well as by the dopamine D2 receptor antagonist haloperidol. Because haloperidol was approximately 30-150-times more potent than (+)-AJ76 or (+)-UH-232 in blocking the effects of either receptor agonist, the results indicate that dopamine D2 receptors play a role in the discriminative stimulus effects of (+)-PD 128907.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed2001

Selective D3 receptor agonist effects of (+)-PD 128907 on dialysate dopamine at low doses.

An involvement of the D3 dopamine receptor in the modulation of extracellular dopamine concentrations is suggested by pharmacological studies. However, recent studies using D3 receptor knock out mice indicated that several functions previously attributed to the D3 receptor are mediated by other receptor types. In the present study, we used the no-net flux microdialysis technique to characterize: (i) basal dopamine dynamics in the ventral striatum of D3 knock out and wild type mice and (ii) the effects of the putative D3-receptor selective agonist (+)-PD 128907. Neither the extracellular dopamine concentration nor the in vivo extraction fraction, an indirect measure of basal dopamine uptake, differed between D3 knock out and wild type mice. Moreover, no differences in potassium (60 mM) or cocaine (5 or 20 mg/kg i.p.) evoked dopamine concentrations were detected between the two genotypes. However, intra-striatal or systemic administration of doses of (+)-PD 128907 that failed to modify dopamine concentrations in knock out mice significantly decreased dialysate dopamine concentrations in the wild type. Comparison of the concentration-response curve for (+)-PD 128907 revealed IC(25) values of 61 and 1327 nM in wild type and knock out mice, respectively, after intra-striatal infusions. Similar differences were obtained after systemic administration of the D3 preferring agonist (IC(25) 0.05 and 0.44 mg/kg i.p. in wild type and knock out mice, respectively). We conclude that the activation of the D3 receptor decreases extracellular dopamine levels and that, at sufficiently low doses, the effects of (+)-PD 128907 on extracellular dopamine are selectively mediated by the D3 receptor.

Animals↗
PubMed2000

Effect of Pd or Au addition on age-hardening in AgMn-based alloys.

OBJECTIVE: The objective of this research was to characterize the age-hardening behavior of AgMn alloys modified with Au or Pd. These alloys are being studied as possible alternatives to Type III dental alloys. METHODS: The age-hardening reactions in Ag-37 at % Mn alloys with 5 at% Au or Pd were investigated by optical microscopy, electrical resistivity, X-ray diffraction and hardness tests. RESULTS: Optical microscopy showed no grain boundary precipitates formed after overaging. The maximum hardness reached by aging in all alloys is about 260 (Hv) and identical to that of traditional AgPdCu dental alloys. The precipitation reactions were retarded with the addition of 5 at% Au or Pd. X-ray diffraction studies suggest a fine precipitate, alpha-Mn, is dispersed within the grain interior. The activation energy for the precipitation reaction is 114 kJ/mol for the AgMn and AgMnAu alloys. This value is about one-half of the activation energy for volume diffusion of manganese in AgMn alloys. SIGNIFICANCE: The age-hardenable AgMn-based alloys modified with Au or Pd can achieve hardness values comparable to those of traditional AgPdCu alloys. Provided the in vivo corrosion resistance of these alloys is adequate, they show promise as a Cu-free alternative material for cast restorations.

Chemical Precipitation↗
PubMed1980

Interaction of Pd(II) glycyl--L-histidine complex with cytidine and GMP. Proton and carbon-13 nmr studies.

1H and 13C nmr studies on the Pd(II)Gly-His complex interaction with cytidine and GMP have shown that the nucleoside binds the palladium complex via N3 nitrogen and the nucleotide binds that complex via N7 nitrogen. The analysis of the Cyd or GMP aromatic ring influence on the chemical shift of the H2 proton or the C2 carbon of imidazole ring has supported the earlier suggestions that nucleoside or nucleotide base and Pd(II) complex plane are almost perpendicular to each other. The Pd(II)Gly-His: Cyd or GMP ternary systems are easily decomposed already in weak basic solutions, which may suggest that the polymerization of Pd(II)Gly-His binary species might be the competitive process in the interactions with nucleosides or nucleotides.

Chemical Phenomena↗
PubMed1999

Structural and cytotoxic study of new Pt(II) and Pd(II) complexes with the bi-heterocyclic ligand mepirizole.

Pd(II) and Pt(II) complexes of formulae [MLCl2], where L = mepirizole, were synthesized and characterized. Two complexes were obtained and studied by different techniques: IR, 1H and 13C NMR and XPS spectroscopies and mass spectrometry (electrospray). The crystal structure of the complex cis-dichloro-4-methoxy-2-(5-methoxy-3-methyl- pyrazol-1-yl)-6-methyl-pyrimidinepalladium(II), [Pd(mep)Cl2], was studied by crystal X-ray diffraction. It consists of discrete molecules with planar geometry. Pd(II) ions are four-coordinated by two mepirizole nitrogen atoms (N1 from the pyrazole ring and N4 from the pyrimidine ring) and two chlorine atoms. The geometry of the PdN2Cl2 chromophore is a distortion of the square-planar coordination. Data from powder pattern X-ray diffraction of cis-dichloro-4-methoxy-2-(5-methoxy-3-methyl-pyrazol-1-yl)-6-methyl- pyrimidineplatinum(II), [Pt(mep)Cl2], demonstrated that the two complexes are isostructural. The cytotoxic activity of both Pd and Pt complexes was checked for six different tumor cell lines and was lower than that of cisplatin. The Pt bound to DNA was also checked and only a low percentage is able to cross the cell membrane.

Animals↗
PubMed1996

Enhancement of peritoneal dialysis: the PD Plus concept.

The need for a peritoneal dialysis modality capable of providing higher clearances of small solutes at a competitive cost with continuous ambulatory peritoneal dialysis (CAPD) has been identified. A new modality of therapy (PD Plus; Fresenius USA, Walnut Creek, CA), which is based on the principles of optimal dwell time and large exchange volumes while the patient is supine, is described. This technique combines automated cycles with a manual diurnal exchange. Seven patients were studied during CAPD and while on PD Plus. Peritoneal Kt/Vurea increased from 0.22 +/- 0.04 to 0.29 +/- 0.07 (P < 0.002), creatinine clearance from 37.69 +/- 2.45 to 51.14 +/- 8.34 L/wk/1.73 m2 (P < 0.005), and normalized protein catabolic rate from 0.74 +/- 0.14 to 0.80 +/- 0.15 g/kg/d during CAPD and PD Plus, respectively, with a mean increase in dialysis solution volume of only 2.76 L. A comparative cost-efficiency analysis demonstrated a highly significant increase in dialysis dose (delta Kt/Vurea 57%) for a small increase in cost (6%) between CAPD and PD Plus. The data suggest that a significant increase in dialysis dose is possible with a minimal increase in the cost of therapy.

Adult↗
PubMed1998

Expression of platelet-derived endothelial cell growth factor (PD-ECGF) and its mRNA in ovarian cancers.

The potential of growth, invasion and metastasis of ovarian cancer cells associated with neovascularization, and the expression of platelet-derived endothelial growth factor (PD-ECGF) and its mRNA in ovarian cancers were determined. The relationship between their expression and histopathological types and clinical stages of ovarian cancers was also analyzed. The levels of PD-ECGF and its mRNA were higher in ovarian cancers than in normal ovaries. Furthermore, some endometrioid carcinomas and serous cystadenocarcinomas of the ovary and some ovarian cancers in stages III and IV expressed remarkably high levels of PD-ECGF and its mRNA. Therefore, in some ovarian cancers, PD-ECGF might be related to advanced stages of ovarian cancers associated with neovascularization.

Adult↗
PubMed1997

The human PD-1 gene: complete cDNA, genomic organization, and developmentally regulated expression in B cell progenitors.

We report the complete cDNA sequence and the genomic structure of the human PD-1 homologue. An analysis of the expression pattern of the human PD-1 gene (hPD-1) and the murine PD-1 gene (mPD-1) in developing bone marrow B-lineage cells was also undertaken. The full length hPD-1 cDNA is 2106 nucleotides long and encodes a predicted protein of 288 amino acid residues. The hPD-1 and mPD-1 genes share 70% homology at the nucleotide level and 60% homology at the amino acid level. Four potential sites for N-linked glycosylation are conserved, as are a stretch of amino acids between two cysteine residues resembling a V-set immunoglobulin domain, and another region containing a motif similar to an immunoreceptor tyrosine-based inhibitory motif. Isolation of the genomic locus of the hPD-1 gene reveals that the gene is composed of five exons located on human chromosome 2 at band q37. The 5' flanking region lacks TATA and CAAT cis-acting elements, but includes a number of potential transcription factor binding sites and a dominant transcription start site. The mPD-1 gene was preferentially expressed in pro-B cells from murine adult bone marrow. Although hPD-1 was not preferentially expressed in pro-B cells from human fetal bone marrow, treatment of isolated pro-B cells with interleukin-7 resulted in a dramatic increase in expression. These data suggest that PD-1 may play a role in B-cell differentiation during the pro-B cell stage.

Amino Acid Sequence↗
PubMed2003

Effects of various steroids on platelet-derived endothelial cell growth factor (PD-ECGF) and its mRNA expression in uterine endometrial cancer cells.

Progestins diminish the estrogen-induced angiogenic potential related to basic fibroblast growth factor (FGF) and vascular endothelial growth factor (VEGF) in uterine endometrial cancer cells. This led us to study the effect of various steroids on the expression of platelet-derived endothelial cell growth factor (PD-ECGF) as the other pertinent angiogenic factor in well-differentiated uterine endometrial cancer cell line Ishikawa. In Ishikawa cells, estradiol induced the expression of PD-ECGF and its mRNA. The estrogen-induced expression was increased approximately two-fold by progesterone and by its metabolite, 17alpha-hydroxyprogesterone, but not by medroxyprogesterone acetate (MPA). Therefore, progesterone and 17alpha-hydroxyprogesterone as endogenous steroids might induce PD-ECGF-related angiogenic potential in uterine endometrial cancer cells, but not MPA as a synthetic steroid. In conclusion, the failure of PD-ECGF induction by MPA might be the great merit of anti-angiogenic treatment with MPA for uterine endometrial cancers.

17-alpha-Hydroxyprogesterone↗
PubMed2003

Economic burden and quality of life impairment increase with severity of PD.

PURPOSE: To define the interrelationship between cost-of-illness, quality of life (QoL) and Parkinson's disease (PD) severity in a common patient management setting in Finland.Scope. Two hundred and sixty consecutive outpatients with idiopathic PD participated. UPDRS, motor fluctuations, QoL, and the use of health care resources were measured. Direct and indirect costs were calculated. CONCLUSIONS: There is a strong relationship between QoL or cost-of-illness on the one hand, and severity of PD on the other. Treatment policies capable of reducing or delaying motor fluctuations would be expected to increase QoL and reduce some of the economic burden of PD.

Aged↗
PubMed2000

Experimental and theoretical studies of the d8-d10 interaction between Pd(II) and Au(I): bis(chloro[(phenylthiomethyl)diphenylphosphine]gold(I))- dichloropalladium(II) and related systems.

The reaction between thioether phosphine gold(I) precursors such as [AuCl(Ph2PCH2SPh)], 1, or [Au(Ph2PCH2SPh)2]CF3SO3 and PdCl2(NCPh)2 affords the new compounds [(AuCl(Ph2PCH2SPh)2PdCl2], 2, and [AuPdCl2(Ph2PCH2SPh)2]CF3SO3, 3. The crystal structure of complex 2 has the sterically unhindered Pd(II) and Au(I) at a distance of 314 pm. Quasirelativistic pseudopotential calculations on [AuPdCl3(PH2CH2SH)(SH2)] models give short Au-Pd distances at the second-order Møller-Plesset (MP2) level and long Au-Pd distances at Hartree-Fock (HF) level. A detailed analysis of the Au-Pd interaction shows dominant dispersion, some ionic contributions, and no net charge transfer between the metals.

Journal Article↗
PubMed2002

Magnetic semiconductor: structural, magnetic, and conducting properties of the salts of the 6-oxoverdazyl radical cation with M(dmit)(2) anions (M = Ni, Zn, Pd, and Pt, dmit = 1,3-dithiol-2-thione-4,5-dithiolate).

Five kinds of (1:1), (1:3), and (2:1) salts of 3-[4-(diethylmethylammonio)phenyl]-1,5-diphenyl-6-oxoverdazyl radical cation [V](+) with M(dmit)(2) anions (M = Ni, Zn, Pd, and Pt, dmit = 1,3-dithiol-2-thione-4,5-dithiolate) ([V](+)[Ni(dmit)(2)](-) (1), [V](+)[Ni(dmit)(2)](3)(-) (2), [V](+)(2)[Zn(dmit)(2)](2-) (3), [V](+)(2)[Pd(dmit)(2)](2-) (4), and [V](+)(2)[Pt(dmit)(2)](2-) (5)) and an iodide salt of [V](+) ([V](+)[I](-) (6)) have been prepared, and the magnetic susceptibilities (chi(M) values) have been measured between 1.8 and 300 K. The chi(M) of the (1:1) Ni salt (1) can be well reproduced by the sum of the contributions from (i) a Curie-Weiss system with a Curie constant (C) of 0.376 K emu/mol and a negative Weiss constant (theta) of -1.5 K and (ii) the one-dimensional Heisenberg antiferromagnetic alternating chain system with 2J(A-B)/k(B) = -274 K (alternation parameter alpha = J(A-C)/J(A-B) = 0.2). The chi(M) of the (1:3) Ni salt (2) can be well explained by the two-term contributions from (i) the Curie-Weiss system with C = 0.376 K emu/mol and theta = -5.0 K and (ii) the dimer system with 2J/k(B) = -258 K. The magnetic properties of 1 and 2 were discussed based on the results obtained by crystal structure analysis and ESR measurements of 1 and 2. The chi(M) values of the (2:1) Zn, Pd, Pt salts 3, 4, and 5 and [V](+)[I](-) salt 6 follow the Curie-Weiss law with C = 0.723, 0.713, 0.712, and 0.342 K emu/mol and theta = -2.8, -3.1, -2.6, and +0.02 K, respectively, indicating that only the spins of the verdazyl radical cation contribute to the magnetic property of these salts. The salts 1, 3, and 5 are insulators. On the other hand, the conductivity (sigma) of the Ni salt 2 and Pd salt 4 at 20 degrees C was sigma = 8.9 x 10(-2) and 1.3 x 10(-4) S cm(-)(1) with an activation energy E(A) = 0.11 and 0.40 eV, respectively. The salts 2 and 4 are new molecular magnetic semiconductors.

Journal Article↗
PubMed2002

Pd(0) and Pt(0) metallocryptands encapsulating a spinning mercurous dimer.

The deep-red, air-stable complexes [Pt(2)Hg(2)(P(2)phen)(3)](PF(6))(2), 1, or [Pd(2)Hg(2)(P(2)phen)(3)](PF(6))(2), 2, (P(2)phen is 2,9-bis(diphenylphosphino)-1,10-phenanthroline) are most conveniently prepared by the stoichiometric reaction of either Pt(dba)(2) or Pd(2)(dba)(3).CHCl(3) (dba is dibenzylideneacetone) with P(2)phen and a single drop of elemental mercury in refluxing dichloromethane under an atmosphere of nitrogen. The (31)P[(1)H] NMR spectrum (CD(3)CN) of 1 shows a single sharp resonance at 43.1 ppm for the phosphorus atoms of the P(2)phen ligand with both (195)Pt ((1)J(P-Pt) = 4350 Hz) and (199)Hg ((2)J(P-Hg) = 620 Hz) satellites indicating the Hg(2)(2+) unit is dynamic. Compound 2 has a similar resonance at 44.9 ppm with (199)Hg satellites ((2)J(P-Hg) = 638 Hz). The (199)Hg NMR (CD(2)Cl(2), vs Hg(OAc)(2)) spectrum of 2 shows a heptet pattern at 833 ppm while for 1 a heptet superimposed on a doublet of heptets is observed at 770.8 ppm. The (195)Pt NMR spectrum of 1 displays a quartet at -3071 ppm with (199)Hg satellites and a (1)J(Pt-Hg) value of 1602 Hz. Characterization of 1 and of 2(BF(4)(2) by single-crystal X-ray diffraction studies confirms the metallocryptand structure consisting of three phosphine-imine ligands forming a D(3) symmetric cage with a Hg(2)(2+) ion in its center coordinated to two phenanthroline rings with the Hg-Hg bond (1, 2.7362(6); 2(BF(4)(2), 2.6881(4) A) oriented perpendicular to the vector between the trigonally coordinated Pt(0) or Pd(0) atoms on each end. The Pt-Hg separations in 1 average 2.8143(6) A while in 2(BF(4)(2) the average Pd-Hg separation is 2.7698(5) A. Excitation into the low energy excitation bands of 1 (475 nm) and 2 (430 nm) produces weak emissions centered at 593 nm with shoulders at 530 and 654 nm in 1 and centered at 524 nm with a shoulder at 545 nm in 2.

Journal Article↗
PubMed2003

Metal-dependent ferro- versus antiferromagnetic interactions in molecular crystals of square Planar (M(II) imino-nitroxide radical) complexes (M = Pt, Pd).

The synthesis and structural, spectral, and magnetic characterizations of two new complexes of formula [Pt(IM(2)Py)Cl(2)] (A) and [Pd(IM(2)Py)Cl(2)] (B) are reported. IM(2)Py stands for the imino-nitroxide radical ligand 2-(ortho-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl. Their crystal structures were solved at room temperature and at 120 K revealing structural phase transitions from pseudo-orthorhombic to monoclinic systems for the two compounds which remain isostructural in the whole temperature range explored. Structural parameters for A: T = 293 K [120 K], monoclinic (P2(1)/n) [P2(1)/c], a = 7.906(2) [7.989(3)] A, b = 17.872(9) [10.168(4)] A, c = 10.357(3) [17.623(6)] A, beta = 90.732(13) degrees [95.940(2)] degrees, Z = 4 [4]. Structural parameters for B: T = 293 K [120 K], monoclinic (P2(1)/n) [P2(1)/c], a = 7.900(3) [7.9730(2)] A, b = 17.907(9) [10.1806(3)] A, c = 10.299(3) [17.7171(4)] A, beta = 90.524(14) degrees [95.747(2)] degrees, Z = 4 [4]. In both complexes, the metal coordination is essentially planar. The average Pt-N, Pt-Cl and Pd-N, Pd-Cl bond lengths are 1.996(6) [1.88], 2.295(2) [2.248(8)] A and 2.015(7) [2.029(8)], 2.287(3) [2.294(3)] A, respectively. The solid state structure is characterized by a pairlike molecular packing stacked in columns parallel to the a axis; this dimer character is reinforced at low temperature. Despite their structural similarity, the investigation of the magnetic properties revealed that dominant ferromagnetic interactions govern the behavior of the Pt derivative A, whereas antiferromagnetic interactions take place for the Pd compound B. A rationalization for this rather intriguing difference is proposed in light of the spin population deduced from density functional theory calculations. The electronic absorption spectra of A and B present structured absorption bands in the visible which are attributed to MLCT transitions. Both compounds are nonluminescent at room temperature. However, a weak emission is detected for A in butyronitrile glasses at 77 K, indicating that the MLCT excited state is strongly quenched at low temperature.

Journal Article↗
PubMed2004

Synthesis and properties of palladium diselenolenes: X-ray crystal structures of [Pd[SeC(R(1))=C(R(2))Se](PBu(3))(2)] [R(1), R(2) = (CH(2))(n), n = 4, 5, 6].

The reaction between [Pd(2)(dba)(3)] (dba = dibenzylideneacetone), tributylphosphine, and a bis(cycloalkeno)-1,4-diselenin leads to either a mononuclear diselenolene [Pd[SeC(R(1))=C(R(2))Se](PBu(3))(2)] or a dinuclear diselenolene [Pd(2)[SeC(R(1))=C(R(2))Se](2)(PBu(3))(2)] [R(1), R(2) = (CH(2))(n), n = 4, 5, 6] depending on the stoichiometry employed. Treatment of the dinuclear diselenolenes with 1,2-bis(diphenylphosphino)ethane (dppe) provides a high-yielding route to the mononuclear species [Pd[SeC(R(1))=C(R(2))Se](dppe)]. All new compounds have been characterized by standard spectroscopic and analytical techniques, in particular by multinuclear NMR spectroscopy; the structure of each of the mononuclear tributylphosphine complexes has been determined by X-ray crystallography. Computational studies show that the observed asymmetry of the diselenolenes in the solid state is a result primarily of intramolecular repulsive interactions between the ligands.

Journal Article↗