Californium polyborate is a covalent compound with formula Cf[B6O8(OH)5]. In this compound the californium is in a +3 oxidation state. This compound is the highest atomic number borate with a visible solid phase. Heavier elements than californium decay too fast to make macroscopic amounts of solid crystals.[1]
Californium polyborate is unusual in that californium is covalently bound to the borate. Californium was expected to resemble lanthanide elements in being highly ionic. The polyborate anion is polarisable and flexible.[2] The 5f, 6d, 7s, and 7p orbitals of californium are all involved on the bonding.[2] Most valence electrons are in the 5f orbital, and a significant fraction (2⁄3) in the 6d orbital, and smaller fractions of one electron are in the 7s and 7p orbitals.[1]
Californium(III) polyborate can be made by autoclaving a californium(III) chloride solution in water with excess boric acid for a week at 240°C. This is then cooled slowly to room temperature for another three days. Water dissolves excess boric acid to leave insoluble crystals of the borate.[1]
Propertiesedit
The californium(III) polyborate solid undergoes a green fluorescence of 525 nm with ultraviolet light of wavelengths 365 or 420 nm.[1] There is also an invisible near infrared fluorescence at 1020 nm induced by green light at 546 nm.[1]
Safetyedit
Californium polyborate is dangerous because of the radioactivity of californium and its decay daughter curium. Between them these elements emit α particles, gamma rays and neutrons.[1]
Referencesedit
^ abcdefghPolinski, Matthew J.; Garner, Edward B.; Maurice, Rémi; Planas, Nora; Stritzinger, Jared T.; Parker, T. Gannon; Cross, Justin N.; Green, Thomas D.; Alekseev, Evgeny V.; Van Cleve, Shelley M.; Depmeier, Wulf; Gagliardi, Laura; Shatruk, Michael; Knappenberger, Kenneth L.; Liu, Guokui; Skanthakumar, S.; Soderholm, Lynda; Dixon, David A.; Albrecht-Schmitt, Thomas E. (23 March 2014). "Unusual structure, bonding and properties in a californium borate". Nature Chemistry. 6 (5): 387–392. Bibcode:2014NatCh...6..387P. CiteSeerX10.1.1.711.6947. doi:10.1038/nchem.1896. PMID 24755589. S2CID 104331283.
^ ab"Unusual structure, bonding, and properties may provide a new possibility for a californium borate". 1 June 2015. Retrieved 29 July 2015.
January 01, 1970
californium, polyborate, californium, polyborate, covalent, compound, with, formula, b6o8, this, compound, californium, oxidation, state, this, compound, highest, atomic, number, borate, with, visible, solid, phase, heavier, elements, than, californium, decay,. Californium polyborate is a covalent compound with formula Cf B6O8 OH 5 In this compound the californium is in a 3 oxidation state This compound is the highest atomic number borate with a visible solid phase Heavier elements than californium decay too fast to make macroscopic amounts of solid crystals 1 Californium III polyborate Names Other names Californium borate Identifiers Properties Chemical formula Cf B6O8 OH 5 Molar mass 526 90 g mol 1 Appearance pale green plates Density 3 842 g cm3 solid Structure Crystal structure monoclinic 1 Space group C2 c Lattice constant a 6 849 A b 18 809 A c 101 36 Aa 90 b 124 72 g 90 Lattice volume V 910 9 Formula units Z 4 Coordination geometry 8 coordinate square antiprism Except where otherwise noted data are given for materials in their standard state at 25 C 77 F 100 kPa Infobox references Californium polyborate is unusual in that californium is covalently bound to the borate Californium was expected to resemble lanthanide elements in being highly ionic The polyborate anion is polarisable and flexible 2 The 5f 6d 7s and 7p orbitals of californium are all involved on the bonding 2 Most valence electrons are in the 5f orbital and a significant fraction 2 3 in the 6d orbital and smaller fractions of one electron are in the 7s and 7p orbitals 1 Contents 1 Formation 2 Properties 3 Safety 4 ReferencesFormation editCalifornium III polyborate can be made by autoclaving a californium III chloride solution in water with excess boric acid for a week at 240 C This is then cooled slowly to room temperature for another three days Water dissolves excess boric acid to leave insoluble crystals of the borate 1 Properties editThe californium III polyborate solid undergoes a green fluorescence of 525 nm with ultraviolet light of wavelengths 365 or 420 nm 1 There is also an invisible near infrared fluorescence at 1020 nm induced by green light at 546 nm 1 Safety editCalifornium polyborate is dangerous because of the radioactivity of californium and its decay daughter curium Between them these elements emit a particles gamma rays and neutrons 1 References edit a b c d e f g h Polinski Matthew J Garner Edward B Maurice Remi Planas Nora Stritzinger Jared T Parker T Gannon Cross Justin N Green Thomas D Alekseev Evgeny V Van Cleve Shelley M Depmeier Wulf Gagliardi Laura Shatruk Michael Knappenberger Kenneth L Liu Guokui Skanthakumar S Soderholm Lynda Dixon David A Albrecht Schmitt Thomas E 23 March 2014 Unusual structure bonding and properties in a californium borate Nature Chemistry 6 5 387 392 Bibcode 2014NatCh 6 387P CiteSeerX 10 1 1 711 6947 doi 10 1038 nchem 1896 PMID 24755589 S2CID 104331283 a b Unusual structure bonding and properties may provide a new possibility for a californium borate 1 June 2015 Retrieved 29 July 2015 Retrieved from https en wikipedia org w index php title Californium III polyborate amp oldid 1213427875, wikipedia, wiki, book, books, library,
