Synthesis and characterization of polyborates templated by cationic copper(II) complexes: Structural (XRD), spectroscopic, thermal (TGA/DSC) and magnetic properties

Abstract

Synthesis and characterization of polyborates templated by cationic copper(II) complexes: structural (XRD), spectroscopic, thermal (TGA/DSC) and magnetic properties.

Hexaborate(2−) and Dodecaborate(6−) Anions as Ligands to Zinc(II) Centres: Self-Assembly and Single-Crystal XRD Characterization of [Zn{κ3O-B6O7(OH)6}(κ3N-dien)]·0.5H2O (dien = NH(CH2–CH2NH2)2), (NH4)2[Zn{κ2O-B6O7(OH)6}2 (H2O)2]·2H2O and (1,3-pnH2)3[(κ1N-H3N{CH2}3NH2) Zn{κ3O-B12O18(OH)6}]2·14H2O (1,3-pn = 1,3-diaminopropane)

“…Compound 2 had a TGA trace consistent with loss of initial interstitial water (<110 °C), loss of ammonia (110-250 °C), and final condensation of hexaborate(2−) anions (250-500 °C). Similar thermal behaviour has been observed in other metal polyborate species [12,13,24,[32][33][34][35] [15]. Magnetic susceptibility χm data for 1-3 were ~ −200 × 10 −6 cm 3 •mol −1 and typical for diamagnetic zinc(II) complexes.…”

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

“…[28]. The B-O bond lengths, OBO and BOB angles observed for the [B 4 O 5 (OH) 4 ] 2− and B(OH) 3 motifs are in accord with previous tetraborate(2-)[47][48][49][50][51][52][53][54][55][56] and polyborates with co-crystallized B(OH)3 [32,33,39,55,57,58]; for full details see the Supplementary Information.…”

“…However, there are no direct anion-anion interactions within the lattice and the B(OH)3 units serve to bridge tetraborate(2-) anions by acting as ′spacers′ to expand the lattice so that it can accommodate the relatively large cation, [Me3N(CH2)2NMe3]. This spacer role for B(OH)3 has been observed before [32,33,39,[55][56][57][58]. With reference to Figure 6 it can be seen that the H-bond structure can be envisaged as ′horizontal′ chains of alternating [B4O5(OH)4] 2-/B(OH)3 units held together by R2 2 (8) interaction, crosslinked by ′vertical′ C2 2 (8) chains (involving O8,H8 … O12,H12 … O5,B1,O2,B3) in a regular 2D arrangement.…”

“…Using Etter nomenclature [46] the H-bond interactions per pentaborate are 3 R2 2 (8) and 1 R2 2 (12) for 2, and 3 R2 2 (8) and 1 C(8) for 3, 7, and 8. Compound 7 adopts the familiar ′herringbone′ structure [29,31] The structural characterization of 9 is considered in more detail in this manuscript since it contains a tetraborate(2-) anion and there are far fewer crystallographic reports in the literature featuring this anion; the anion is found partnered with 2Na + in the well-known borax [47,48] but is less commonly found with non-metal cation [40,[49][50][51][52] or transition metal cation salts [53][54][55][56].…”

Two 1-D Coordination Polymers Containing Zinc(II) Hexaborates: [Zn(en){B6O7(OH)6}]·2H2O (en = 1,2-diaminoethane) and [Zn(pn){B6O7(OH)6}]·1.5H2O (pn = 1,2-diaminopropane)

“…The hexaborate(2−) ligand is tridentate to the Zn(II) metal center with Zn1-O11, Zn1-O12, and Zn1-O13 distances of 2.071(2), 2.017(2), and 2.648 are not significantly different from those of 1 or other reported structures [36][37][38]. The structure of 2 displays numerous structure-directing H-bond interactions, in a similar manner to those observable in 1.…”