The structure and classification of complex borates

Abstract

The review is devoted to systematic analysis of polyborate structures based on the recognition of fundamental building blocks. A wide range of inorganic polyborates are analyzed. The approach makes it possible to identify the place of new compounds among previously investigated ones, to compare their structures and to reveal structural features in order to substantiate the properties of novel materials and to optimize their search. The bibliography includes 87 references.

Pentaborate(1-) Salts and a Tetraborate(2-) Salt Derived from C2- or C3-Linked Bis(alkylammonium) Dications: Synthesis, Characterization, and Structural (XRD) Studies

“…Synthetic strategies to prepare pentaborate(1-) salts partnered with organic cations include the reaction of a free base amine with B(OH) 3 in aqueous solution or use of OHactivated ion-exchange resins with quaternary ammonium halide salts [5]. Schubert and co-workers [19] have successfully applied the former method to α,ω-diaminoalkanes and have isolated a number of pentaborate(1-) salts containing a +2 diammonium cations of composition [H 3 N(CH 2 ) x NH 3 ][B 5 O 6 (OH) 4 ] 2 (x = 5, 6, [8][9][10][11][12]. In this study, the pentaborate (1-) (6) were readily prepared as crystalline solids from aqueous solution in yields of 87-99% by the reaction of 10 equivalents of B(OH) 3 with the diaminoalkane in aqueous solution at room temperature.…”

“…Salts and neutral species containing polyoxidoborate (polyborate) anions occur as minerals and many synthetic derivatives have now also been prepared [1][2][3][4][5]. These compounds are structurally diverse, with the polyborate anions generally comprised of trigonal planar 3-coordinate and tetrahedral 4-coordinate boron centres, linked via oxygen bridges with as many terminal OH or O − groups as is necessary to complete the required geometry at boron [6][7][8][9][10][11]. Some polyborate salts are sold as bulk chemicals for use in the glass/vitreous, fire retardant, and agricultural industries [12][13][14], whilst other synthetic polyborates have interesting and specialized physical e.g., semiconducting, luminescent, non-linear optical (NLO) properties [5,15].…”

“…Synthesis, Spectroscopic and Analytical Data for 6Following the method as described for 1, B(OH) 3 (6.2 g; 100.2 mmol) and Et 2 N(CH 2 ) 3 NEt 2 (1.86 g; 10.0 mmol) gave crude product of 6 (5.4 g; 87%). C11 H 36 B 10 N 2 O 20 . Anal.…”

Oxidopolyborate anions templated by transition-metal complex cations: Self-assembled syntheses and structural studies (XRD) of [Co(NH3)6]2[B4O5(OH)4]3·11H2O, [Ni(phen)3][B7O9(OH)5].9.5H2O and [Zn(dac)2(H2O)2][B7O9(OH)5]·H2O

“…Oxidopolyborate (borate) anions are a well-known class of compounds with many synthetic materials adding to the several hundred known naturally occurring minerals [1][2][3][4]. Many of these compounds have been structurally characterised by XRD studies and their structures range from simple partially condensed insular isolated anions through to fully condensed anhydrous complex 3-D networks [5][6][7][8][9][10].…”

“…Non boron-bridging oxygen atoms normally exist as hydroxyl groups in isolated structures whereas Ogroups are not uncommon in the more condensed networks. Cations play an important role in stabilizing such structures though solid-state interactions with the anions [1][2][3][4][5][6][7][8][9][10]. Borates are important industrially and are used in many vitreous, agricultural, biostatic, and fire retardant applications [11,12].…”