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The Intermetallic Zirconium Compounds ZrNiAl, ZrRhSn, and ZrPtGa - Structural Distortions and Metal-Metal Bonding in Fe2P Related Compounds Markus F. Zumdick, R olf-D ieter Hoffmann, Rainer Pöttgen* Anorganisch-Chemisches Institut, Universität Münster, Wilhelm-Klemm-Straße 8 , D-48149 Münster, Germany Z. Naturforsch. 54 b, 45-53 (1999); received August 20, 1998 Intermetallic Compounds, Crystal Structure, Superstructure, Chemical Bonding ZrNiAl, ZrPtGa, and ZrRhSn have been prepared by reacting the elements in an arc-melting furnace and subsequent annealing at

Unconventional strength additives Makhlouf Laleg and Zvan I. Pikulik, Pulp and Paper Research Institute of Canada, Pointe Claire, Quebec, Canada Keywords: Additives. Wet webs, Wet strength, Dry strength, Cationic compounds, Aldehyde groups, Starch. Zirconium compounds. Bisulfite pulps. Kraft pulps. Thermomechanical pulps. SUMMARY: Unconventional additives for increasing the strength of never-dried wet webs, dry paper and rewetted paper were investigated. It was found that handsheets made from bisulphite pulps or kraft pulps can be reinforced by cationic

the heterocycle, but also with more com- plex pyrazole ligands likeHL1 andHL2. The crystal structure of 2 represents the first for a homoleptic zirconium compound of that type. Experimental Section General procedures and methods: Reactions were carried out in NMR tubes which were loaded under an atmosphere of dry argon in a glove box. Solvents were vacuum transferred into the NMR tubes and the tubes were flame-sealed. Solvents were dried according to established procedures. Zr(CH2Ph)4 [11] as well as HL1 and HL2 [8] were synthesized according to the re- ported

nature of amorphous state ( Fu, Sun & Zhang, 2013 ; Louzgine-Luzgin & Inoue, 2013 ; Qiao, Pelletier & Casalini, 2013 ; Kulikova et al., 2015 ; Klumov, Ryltsev & Chtchelkatchev, 2016 ). Zirconium can also be a part of high entropy alloys, known for their structural and phase formation features ( Yurchenko et al., 2017 ; Zhao et al., 2017 ). Zirconium compounds (oxide, alloys, and salts) are widely used as catalysts, for example in redox reactions and isomerization reactions ( Zhang & Li, 2009 ; Molnar, 2011 ; Vining, Strunk & Bell, 2011 ; Cao et al., 2016

180 Ο . Η . W H E E L E R and Μ . L . M C C L I N , Chemical Effects in the Neutron Activation Radiochiinica Acta with cupferron, with another x/3 remaining as a non-ex- tractable chloroform soluble fraction. Only 2% of the activity consisted of a fraction which was extractable with hydrochloric acid, but did not complex with cupferron (see Table 1). In distribution studies on the unactivated material (see Table 2), the zirconium compound remained predominately (82%) in the hydrochloric fraction. Under these conditions Zr IV complexes completely with

biodegradable copolymers with low-toxicity zirconium compounds. V. Multiblock and random copolymers of L-lactide with trimethylene carbonate obtained in copolymerizations initiated with zirconium(IV) acetylacetonate, Journal of Polymer Science: Part A: Polymer Chemistry, Vol. 44, pp. 3184– 3201, 2006 [19] Bero M., Dobrzyński P., Kasperczyk J., Application of zirconium (IV) acetylacetonate to the copolymerization of glycolide with ε-caprolactone and lactide, Polymer Bulletin, 42, pp. 131–139, 1999 [20] Dobrzyński P., Initiation process of L-lactide polymerization carried out

REFERENCES [1] Aiken B, Hsu WP, Matijevic E.: Preparation and properties of uniform mixed and coated colloidal particles .5. Zirconium compounds, J. Mat. Sci. 25 (1990) 1886-1894. [2] Tadros TF: Correlation of viscoelastic properties of stable and flocculated suspensions with their interparticle interactions, Adv. Colloid Interf. Sci., 68 (1996) 97-200. [3] Yanez JA, Laarz E, Bergström L: Viscoelastic properties of particle gels, J. Colloid Interf. Sci., 209 (1999) 162-172. [4] Rueb CJ, Zukoski CF: Viscoelastic properties of colloidal gels, J. Rheol., 41 (1997

remaining as a non-ex- tractable chloroform soluble fraction. Only 2% of the activity consisted of a fraction which was extractable with hydrochloric acid, but did not complex with cupferron (see Table 1). In distribution studies on the unactivated material (see Table 2), the zirconium compound remained predominately (82%) in the hydrochloric fraction. Under these conditions Zr IV complexes completely with cupferron [7, 8] and since there are no other stable compounds of zirconium and cyclopentadiene, the activity in the hydrochloric acid fraction (2%) must be

.8430(1) Å, is identical with that observed in the corresponding zirconium compound: d(Zr—As) = 2.8446(3) Å [1]. Z. Kristallogr. NCS 222 (2007) 369-370 / DOI 10.1524/ncrs.2007.0157 369 © by Oldenbourg Wissenschaftsverlag, München Crystal: metallic, irregular, size 0.030 × 0.025 × 0.010 mm Wavelength: Ag K radiation (0.56080 Å) : 208.2 cm−1 Diffractometer, scan mode: Rigaku R-AXIS RAPID, / 2max: 122.6° N(hkl)measured, N(hkl)unique: 5512, 108 Criterion for Iobs, N(hkl)gt: Iobs > 2 (Iobs), 957 N(param)refined: 11 Programs: SHELXS-97 [2], SHELXL-97 [3], WinCSD [4] Table 1

regeneration. Int. J. Biolog. Macromol. 44, 222-228 [38] Dobrzyński, P., Kasperczyk, J., Janeczek, H., Bero, M., (2001). Synthesis of Biodegradable Copolymers with the Use of Low Toxic Zirconium Compounds. 1. Copolymerization of Glycolide with L-Lactide Initiated by Zr(Acac)4. Macromolecules, 34 (15), 5090-5098 [39] Adamus, G., Kowalczuk, M., (2008). Anionic Ring-Opening Polymerization of -Alkoxymethyl-Substituted-Lactones. Biomacromolecules, 9, 696-703 [40] Patent Nr EP 2325 355 B1 nt.: System for electrospinning of fibers, Twórcy: Krucińska I., Gliścińska E., Chrzanowski M