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  • 1
    Electronic Resource
    Electronic Resource
    Use of soil transfer for reforestation on abandoned mined lands in Alaska (1993)
    Springer
    Mycorrhiza 3 (1993), S. 97-106 
    Details
    ISSN: 1432-1890
    Keywords: Soil transfer ; Reforestation ; Populus ; Phosphorus ; Boreal forest
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Soil transfers, presumed to contain mycorrhizal fungal inoculum from a native plant community, were applied to rooted cuttings and volunteer plants of Populus balsamifera L. to improve their growth on an abandoned mined site in south central Alaska. The objectives of the study were to determine (1) if these soil transfers could be substituted for additional P fertilizer when applied with a base level of NP fertilizer to improve growth, and (2) if P added to treatments receiving a base level of NP fertilizer and soil transfer would suppress mycorrhizal formation. Physical dimensions of plants were measured near the beginning and end of each of two growing seasons. Several plants per plot were harvested at the end of year 2 to determine mycorrhizal formation, current growth, and leaf nutrient concentrations. Plant height was significantly increased only when soil transfer and additional P treatments were combined. Response to additions of P fertilization alone or soil transfer alone were not significantly different from each other. Current twig growth increased with either treatment alone or both combined. Soil transfer on cuttings resulted in more ectomycorrhizal formation than either the control or additional P. Leaf N concentrations on cuttings and volunteers increased when plants were treated with soil transfer. Similar growth responses were achieved by soil transfers or additional P, but mycorrhizal formation was improved with the soil transfer treatments. P added to the base level plus soil transfer did not suppress or improve mycorrhizal formation compared to that with soil transfer alone.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00208917
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  • 2
    Electronic Resource
    Electronic Resource
    Use of soil transfer for reforestation on abandoned mined lands in Alaska (1993)
    Springer
    Mycorrhiza 3 (1993), S. 107-114 
    Details
    ISSN: 1432-1890
    Keywords: Soil transfer ; Reforestation ; Populus ; Alnus ; Boreal forest
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Soil transfers from an intermediate successional site and a mature forest site were applied to Populus balsamifera L. cuttings and Alnus crispa (Ait.) Pursh seedlings placed on an abandoned mined site in south central Alaska to improve plant establishment. Mycorrhizal fungi in the soil transfers from the two successional stages were hypothesized to have different effects on plant species that colonize disturbed sites at different times or on different substrates. The site consisted of coarse, dry, low-nutrient spoils and was naturally colonized by scattered P. balsamifera but not A. crispa, although seed sources for both were adjacent to the site. Physical dimensions of the transplanted seedlings and cuttings were measured at the beginning and end of each growing season. Selected plants were harvested at the end of the 2-year study and examined for mycorrhizal formation, current growth, and leaf tissue nutrient concentrations. Both plant species were taller when treated with the soil transfers from the mature forest than with soils from the intermediate site although the increase for A. crispa was greater. Physical dimensions, current growth, and nutrient concentrations were greater when A. crispa was treated with the mature soil transfer compared with the intermediate soil transfer. Mycorrhizae which infected Alnus were predominantly a brown woody type, while other types accounted for greater relative mycorrhizal infection percentage on Populus. Insufficient quantities of mycorrhizal inoculum of suitable species, as well as low moisture and low nutrient conditions, may be factors limiting A. crispa colonization on primary disturbed sites in south central Alaska.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00208918
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  • 3
    Electronic Resource
    Electronic Resource
    Cyclooctatetraen-Dihydropentalen-Umlagerung von Perchlor-COT und einige Polyhalogenderivate des Bicyclo [3.3.0] octans (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 2156-2165 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cyclooctatetraene-Diydropentalene Rearrangement of Perchloro-COT and some Polyhalogenated Bicyclo[3.3.0]odane DerivativesPerchloro-COT rearranges at 180°C into the dihydropentalenes 2 and 4. Chlorination of 1 or 2 gives the tetrahydropentalene 5a, while 4 is chlorinated to 7a. On further chlorination of 5a and 7a the hexahydropentalene 8 is formed. The structure of these compounds is confirmed by 13C. n.m.r. spectra and chemical reactions of 2, 4, and 5a induced by acids and nucleophilic reagents with formation of the derivatives 9-14. The dechlorination of 2 or 4 to a red dimer of perchloropentalene (16) is characteristic.
    Notes: Perchlor-COT1 lagert sich bei 180°C in die Dihydropentalene 2 und 4 um. Die Chlorierung von 1 oder 2 führt zu dem Tetrahydropentalen 5a, während die von 4 das Tetrahydropentalen 7a ergibt. Bei weiterer Chlorierung gehen 5a und 7a in das gleiche Hexahydropentalen 8 über. Die Struktur dieser Verbindungen ergibt sich am ihren 13C-NMR-Spektren und den chemischen Reaktionen von 2, 4 und 5a mit Säuren und nucleophilen Agentien zu den Derivaten 9-14. Besonders charakteristisch ist die Dechlorierung von 2 oder 4 zu einem roten Dimeren des Perchlorpentalens (16).
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060709
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  • 4
    Electronic Resource
    Electronic Resource
    Dimere polyhalogenierter Benzocyclobutadiene (1973)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 2825-2831 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Dimers of Polyhalogenated BenzocyclobutadienesThe dimerization of per- and polyhalogenated benzocyclobutadienes 2 and 10, prepared by dehalogenation of 1 and 3 or dehydrohalogenation of 9, proceeds unusually to give only „linear“ dimers. When 10a is generated in the presence of 1,3-diphenylisobenzofuran the Diels-Alder addukt 14 is obtained. In boiling toluene the dimers 4 and 12 are isomerized to dibenzo[a,e]cyclooctenes 6 and 13. The perchlorinated derivative 6a splitts off chlorine at 400°C to form a dibenzopentalene 7.
    Notes: Die Dimerisation der per- und polyhalogenierten Benzocyclobutadiene 2 und 10, die durch Dehalogenierung bzw. Dehydrohalogenierung aus den Vorstufen 1 und 3 bzw. 9 erzeugt werden, verläuft insofern ungewöhnlich, als sie nur „lineare“ Dimere ergibt. In Gegenwart von 1,3-Diphenylisobenzofuran läßt sich 10a in dem Diels-Alder Addukt 14 abfangen. Die Dimeren 4 und 12 lagern sich in siedendem Toluol in die entsprechenden Dibenzo[a,e]-cyclooctene 6 und 13 um. Das Perchlorderivat 6a spaltet bei 400°C Chlor ab zum Dibenzopentalen 7.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19731060910
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  • 5
    Electronic Resource
    Electronic Resource
    Water-Exchange Mechanism of Tetraaquapalladium(II). A Variable-Pressure and Variable-Temperature Oxygen-17 NMR StudyPart 23 of the series ‘High-Pressure NMR Kinetics’. For part 22, see [1]. (1984)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 67 (1984), S. 1453-1460 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Water exchange of square-planar Pd(H2O)24+ has been studied as a function of temperature (240 to 345 K) and pressure (0.1 to 260 MPa, at 324 K) by measuring the 17/O-FT-NMR line-widths of the resonance from coordinated water at 27.11 and 48.78 MHz. The following exchange parameters were obtained: k298ex = (560 ± 40) s-1, ΔH* = (49.5 ± 1.9) kJ mol-1, ΔS* = - (26 ± 6) J K-1 mol-1 and ΔV* = - (2.2 ± 0.2) cm3 mol-1. The values refere to an aqueous perchlorate medium with an ionic strength between 2.0 and 2.6 m and a perchloric-acid concentration between 0.8 and 1.7 m, and are interpreted in terms of an associative (a) activation for the exchange. The exchange rate for Pd(H2O)24+ is 1.4 × 106 times faster than for Pt(H2O)24+ at 298 K. A comparison with reactions between other nucleophiles and Pd(H2O)24+ is also made.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19840670605
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  • 6
    Electronic Resource
    Electronic Resource
    Water Exchange on Hexaaquavanadium(III): a Variable-Temperature and Variable-Pressure 17O-NMR Study at 1.4 and 4.7 TeslaPart 24 of the series ‘High-Pressure NMR Kinetics’. Part 23: [1].These results are part of the Ph. D. thesis of A. H., University of Lausanne, 1984. (1985)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 68 (1985), S. 508-521 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Water exchange on hexaaquavanadium (III) has been studied as a function of temperature (255 to 413 K) and pressure (up to 250 MPa, at several temperatures) by 17O-NMR spectroscopy at 8.13 and 27.11 MHz. The samples contained V3+ (0.30-1.53 m), H+ (0.19-2.25 m) and 17O-enriched (10-20%) H2O. The trifluoromethanesulfonate was used as counter-ion, and, contrary to the previously used chloride or bromide, CF3SO3- is shown to be non-coordinating. The following exchange parameters were obtained: kex298 = (5.0 ± 0.3) · 102 s-1, ΔH* = (49.4 ± 0.8) kJ mol-1, ΔS* = -(28 ± 2) JK-1 mol-1, ΔV* = -(8.9 ± 0.4) cm3 mol-1 and Δβ* = -(1.1 ± 0.3) · 10-2 cm3 mol-1 MPa-1. They are in accord with an associative interchange mechanism, Ia. These results for H2O exchange are discussed together with the available data for complex formation reactions on hexaaquavanadium(III). A semi-quantitative analysis of the bound H2O linewidth led to an estimation of the proportions of the different contributions to the relaxation mechanism in the coordinated site: the dipole-dipole interaction hardly contributes to the relaxation (less than 7%); the quadrupolar relaxation, and the scalar coupling mechanism are nearly equally efficient at low temperature (∼ 273 K), but the latter becomes more important at higher temperature (75-85% contribution at 360 K).
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19850680224
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  • 7
    Electronic Resource
    Electronic Resource
    Variable-Temperature and Variable-Pressure 17O-NMR Study of Water Exchange of Hexaaquaaluminium(III)Part 25 of the series ‘High-Pressure NMR Kinetics’. Part 24: [1].These results are part of the Ph. D. thesis of D. H.-C., University of Lausanne, 1984. (1985)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 68 (1985), S. 545-554 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The transverse relaxation rate of H2O in Al(H2O)63+ has been measured as a function of temperature (255 to 417 K) and pressure (up to 220 MPa) using the 17O-NMR line-broadening technique, in the presence of Mn(II) as a relaxation agent. At high temperatures the relaxation rate is governed by chemical exchange with bulk H2O, whereas at low temperatures quadrupolar relaxation is prevailing. Low-temperature fast-injection 17O-NMR was used to extend the accessible kinetic domain. The samples studied contained Al3+ (0.5 m), Mn2+ (0.2-0.5 m), H+ (0.2-3.1 m) and 17O-enriched (20-40%) H2O. Non-coordinating perchlorate was used as counter ion. The following H2O exchange parameters were obtained: kex298 = (1.29 ± 0.04) s-1, ΔH* = (84.7 ± 0.3) kJ mol-1, ΔS* = +(41.6 ± 0.9) J K-1 mol-1, and ΔVex* = +(5.7 ± 0.2) cm3 mol-1, indicating a dissociative interchange, Id, mechanism. These results of H2O exchange on Al(H2O)63+ are discussed together with the available complex-formation rate data and permit also the assignment of Id mechanisms to these latter reactions.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19850680302
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  • 8
    Electronic Resource
    Electronic Resource
    Dimethylformamide-Exchange Mechanism on Some First-Row Divalent Transition-Metal IonsPart 33 of the series ‘High-Pressur NMR Study’. Part 32: [1].Taken in part from the diploma work of C. Cossy, Université de Lausanne, 1983.This work was presented in part at the 24th International Conference on Coordination Chemistry, Athens, Greece, August 1986. (1987)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 70 (1987), S. 1516-1525 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The effect of temperature on the dimethylformamide exchange on Mn(DMF)2+6 and Fe(DMF)2+6 has been studied by 13C- and 17O-NMR, respectively, yielding the following kinetic parameters: k298 equals; (2.2±0.2). 106 S-1, ΔH≠ = 34.6 ± 1.3 kJ mol-1, ΔS≠ = -7.4 ± 4.8 J K-1mol-1 for Mn2+ and K298 = (9.7 ± 0.2).105 S-1, Delta;H≠ = 43.0 ± 0.9 kJ mol-1, ΔS≠ = + 13.8 ± 2.8 J K-1mol-1 for Fe2+. The volumes of activation, ΔV≠ in cm3mol-1, derived from high-pressure NMR on these metal ions, together with the previously published activation volumes for Co2+ and Ni2+ (+2.4 ± 0.2 (Mn2+), +8.5 ± 0.4 (Fe2+) +9.2 ± 0.3 (Co2+), + 9.1 ± 0.3 (Ni2+)) give evidence for a dissociative activation mode for DMF exchange on these high-spin first-row transition-metal divalent ions. The small positive ΔV≠ value observed for DMF exchange on Mn2+ seems to indicate that a mechanistic changeover also occurs along the series, (probably from Id to D), as for the other solvents previously studied (Ia to Id, for H2O, MeOH, MeCN). This changeover is shifted to the earlier elements of the series, due to more pronounced steric crowding for dimethylformamide hexasolvates.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19870700608
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  • 9
    Electronic Resource
    Electronic Resource
    The solution structure and reactivity of decavanadate (1988)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 71 (1988), S. 1406-1420 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The oxygen-exchange reaction of V10O286- with bulk water has been followed by time-dependent 17O-NMR spectroscopy (buffered solutions, pH ∼ 5.5, [V10]total ∼ 0.17m, T = 298 K). It is shown that all seven structurally different sites of O-atoms are kinetically similar but, in contrast to earlier studies, not identical (6 h ≤ ‘t1/2’ ≤ 11 h). The kinetic similarity of the various structural sites implies the some (but not full) O scrambling is involved. Two possible mechanisms with a ‘half-bonded’ and an ‘open’ intermediate are discussed in detail to interpret the experimental results. A computer simulation of the exchange reaction based on these models is presented. It is shown that the ‘half-bonded-intermediate’ mechanism is consistent with the experimental data and the following parameters are calculated: formation of the intermediate: k1 = 5.8 · 10-3 s-1, k-1 = 6.7 · 10-2 s-1, [intermediate]∞ ≈ 8%; all activated O-atoms exchange within the lifetime of the intermediate (τ ∼ 15 s), and the calculated exchange rate of the intermediate (k2 ≥ 0.60 s-1) is consistent with earlier assumptions (k2 ≈ 0.5 s-1). It is shown that a simulation based on the ‘open-intermediate’ mechanism results in kinetic parameters which are not consistent with the kinetics of the formation of cyclic metavanadates ((VO3-)n, n = 4,5) from decavanadate, since the required formation rate is by a factor ∼ 102 too fast, and the equilibrium concentration of metavanadates is by a factor of ∼ 2 too large (under the conditions of the O-exchange experiments of decavanadate (T = 298 K, [V10]total ≈ 0.17m, pH ∼ 5.55) the total amount of metavanadates present is ∼ 8%, with [(VO3-)4]/[(VO3-)5] ∼ 4:1; a qualitative analysis of the kinetics of the formation of metavanadates (vo kinetics; the exact mechanism of the back-reaction (at least second-order) is not known with certainty) leads to k1 ≥ 4·10-5 s-1). O exchange of decavanadates via equilibrated metavanadates would lead to full scrambling of the O sites and is not consistent with the observed differences in the exchange rates. From the qualitative kinetic parameters of the metavanadate formation kinetics, it can be concluded that any contribution of an ‘open’ or an ‘metavanadate’ mechanism is of the order of 1-2% at most.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19880710605
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  • 10
    Electronic Resource
    Electronic Resource
    Quantitative Formation in Water of [Ru(CO)(H2O)5]2+ from Hexaaquaruthenium(II) and Carbon Monoxide (1991)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 74 (1991), S. 1236-1238 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: High-pressure 17O- and 13C-NMR show that [Ru(H2O)6]2+ reacts quantitatively with carbon monoxide (50 bar) in water to form [Ru(CO)(H2O)5]2+.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19910740611
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