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"Nitrogen"
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Synthesis and Characterization of Iron Bispyridine Bisdicyanamide, FeCsub.5Hsub.5Nsub.2Nsub.2sub.2
Fe[C[sub.5]H[sub.5]N][sub.2][N(CN)[sub.2]][sub.2] (1) was synthesized from a reaction of stoichiometric amounts of NaN(CN)[sub.2] and FeCl[sub.2]·4H[sub.2]O in a methanol/pyridine solution. Single-crystal and powder diffraction show that 1 crystallizes in the monoclinic space group I2/m (no. 12), different from Mn[C[sub.5]H[sub.5]N][sub.2][N(CN)[sub.2]][sub.2] (P2[sub.1]/c, no. 14) due to tilted pyridine rings, with a = 7.453(7) Å, b = 13.167(13) Å, c = 8.522(6) Å, β = 114.98(6)° and Z = 2. ATR-IR, AAS, and CHN measurements confirm the presence of dicyanamide and pyridine. Thermogravimetric analysis shows that π-stacking interactions of the pyridine rings play an important role in structural stabilization. Based on DFT-optimized structures, a chemical bonding analysis was performed using a local-orbital framework by projection from a plane-wave basis. The resulting bond orders and atomic charges are in good agreement with the expectations based on the structure analysis. SQUID magnetic susceptibility measurements show a high-spin state Fe[sup.II] compound with predominantly antiferromagnetic exchange interactions at lower temperatures.
Journal Article
Too much of a good thing
All biological systems need reactive nitrogen, but historically it has been in short supply. [...] the end of the nineteenth century, the main agricultural source was fixation of N2 by symbiotic bacteria in legumes planted for that purpose, combined with careful recycling of the limited amount of nitrogen in manure.
Journal Article
The California nitrogen assessment : challenges and solutions for people, agriculture, and the environment
\"Nitrogen is indispensable to all life on Earth. However, humans now dominate the nitrogen cycle and nitrogen emissions resulting from human activity involve real costs: water and air pollution, climate change, and detrimental effects for human health, biodiversity, and natural habitat. Too little nitrogen limits ecosystem processes, while too much nitrogen transforms ecosystems profoundly. The California Nitrogen Assessment is the first comprehensive accounting of nitrogen flows, practices, and policies for California; encompassing all nitrogen flows--not just those associated with agriculture--and their impacts on ecosystem services and human wellbeing. How California handles issues of nitrogen will be of interest nationally and internationally, and the goal of the assessment is to more effectively link science with action and to produce information that informs both future policy and solutions to nitrogen pollution. This book also provides a model for application of integrated ecosystem assessment methods at regional and state (sub-national) levels.\"--Provided by publisher.
Book
Stable Nitrogen Isotopes as an Effective Tool for Estimating the Nitrogen Demand of IBroussonetia papyrifera/I Vent Seedlings under Variable Nitrate Concentrations
Poor growth is often observed in artificial young forests due to insufficient inorganic nitrogen in karst soils. However, little is known about the assimilatory demand of the whole plant for nitrate and the partitioning of nitrate assimilation in roots and leaves in woody plants grown in karst habitats. In this study, Broussonetia papyrifera (L.) Vent (B. papyrifera) seedlings were grown under nearly hydroponic conditions. The isotope mass balance approach was employed to quantify the δ[sup.15]N values of the N assimilates in plant organs and in whole plants for B. papyrifera seedlings grown at different nitrate concentrations. The δ[sup.15]N values of the N assimilates in the whole B. papyrifera seedlings showed a rising trend with increasing nitrate concentration. Increasing the supply of nitrate decreased the leaf-root difference in the δ[sup.15]N values of the N assimilates for B. papyrifera seedlings. Quantifying the δ[sup.15]N values of N assimilates in the whole B. papyrifera seedlings grown under different nitrate concentrations contributes to estimating the assimilatory demand of the B. papyrifera seedlings for nitrate. The leaf-root difference in the δ[sup.15]N values of the N assimilates can be used to estimate the partitioning of nitrate assimilation in the roots and leaves.
Journal Article
The nitrogen cycle
\"Nitrogen is a common element found as a gas in the air we breathe as well as in other forms in water and soil. Nitrogen is essential for all life on Earth. This informative book explains how the Earth's supply of nitrogen moves in different forms in a cycle from the air to the soil to living things. Highly readable text and supportive images help explain such processes as fixation, nitrification, and dentrification, as well as the important role of bacteria in the nitrogen cycle. Feature boxes highlight examples of the ways in which human activity, such as adding more nitrogen to the soil to make plants grow faster, releases harmful greenhouse gases into the air interfering with the nitrogen cycle. Readers are encouraged to find ways to take action and find solutions\"-- Provided by publisher.
Book
Synthesis, Structure and Antimicrobial Activity of New Co Complex with Ibis/I-Morpholino/Benzoimidazole-Is/I-Triazine Ligand
A new Co(II) perchlorate complex of the bis-morpholino/benzoimidazole-s-triazine ligand, 4,4′-(6-(1H-benzo[d]imidazol-1-yl)-1,3,5-triazine-2,4-diyl)dimorpholine (BMBIT), was synthesized and characterized. The structure of the new Co(II) complex was approved to be [Co(BMBIT)[sub.2](H[sub.2]O)[sub.4]](ClO[sub.4])[sub.2]*H[sub.2]O using single-crystal X-ray diffraction. The Co(II) complex was found crystallized in the monoclinic crystal system and P21/c space group. The unit cell parameters are a = 22.21971(11) Å, b = 8.86743(4) Å, c = 24.38673(12) Å and β = 113.4401(6)°. This heteroleptic complex has distorted octahedral coordination geometry with two monodenatate BMBIT ligand units via the benzoimidazole N-atom and four water molecules as monodentate ligands. The hydration water and perchlorate ions participated significantly in the supramolecular structure of the [Co(BMBIT)[sub.2](H[sub.2]O)[sub.4]](ClO[sub.4])[sub.2]*H[sub.2]O complex. Analysis of d[sub.norm] map and a fingerprint plot indicated the importance of O···H, N···H, C···H, C···O, C···N and H···H contacts. Their percentages are 27.5, 7.9, 14.0, 0.9, 2.8 and 43.5%, respectively. The sensitivity of some harmful microbes towards the studied compounds was investigated. The Co(II) complex has good antifungal activity compared to the free BMBIT which has no antifungal activity. The Co(II) complex has good activity against B. subtilis, S. aureus, P. vulgaris and E. coli while the free BMBIT ligand has limited activity only towards B. subtilis and P. vulgaris. Hence, the [Co(BMBIT)[sub.2](H[sub.2]O)[sub.4]](ClO[sub.4])[sub.2]*H[sub.2]O complex has broad spectrum antimicrobial action compared to the free BMBIT ligand.
Journal Article