Three Polyborates with High-Symmetry [B₁₂O₂₄] Units Featuring Different Dimensions of Anion Groups

Abstract

were synthesized via the high-temperature solution method. All of them feature high-symmetry [B 12 O 24 ] units, yet their anion groups exhibit distinct dimensions. LiNa 11 B 28 O 48 features a three-dimensional anionic structure of 3 [B 28 O 48 ] ∞ framework, which is composed of three units: [B 12 O 24 ], [B 15 O 30 ], and [BO 3 ]. Li 1.45 Na 7.55 B 21 O 36 possesses a one-dimensional anionic structure of 1 [B 21 O 36 ] ∞ chain consisting of [B 12 O 24 ] and [B 9 O 18 ] units. The anionic structure of Li 2 Na 4 Ca 7 Sr 2 B 13 O 27 F 9 is composed of two zero-dimensional isolated units, namely, [B 12 O 24 ] and [BO 3 ]. The novel FBBs [B 15 O 30 ] and [B 21 O 39 ] are present in LiNa 11 B 28 O 48 and Li 1.45 Na 7.55 B 21 O 36 , respectively. The anionic groups in these compounds exhibit a high degree of polymerization, thereby augmenting the structural diversity of borates. And the crystal structure, synthesis, thermal stability, and optical properties were meticulously discussed to guide the synthesis and characterization of novel polyborates.

Research Progress of Iron Catalysts with N,N,N‐tridentate Ligands for Ethylene Polymerization

“…Among the bis(arylimino)pyridine iron catalysts, the commonly used cocatalysts are MAO and MMAO, and there are some other cocatalysts ( iso ‐butylaluminoxane, ethylaluminoxane and alkylaluminum/urea hybrid) that are mainly used for ethylene oligomerization [32,69–76] . Organoboride cocatalysts show unsatisfactory results in stability and anion coordination capacity, and they are rarely used as activators of the bis(arylimino)pyridine iron catalyst [77–81] . MAO is typically produced via controlled hydrolysis of trimethylaluminum (TMA), leading to a rather complex mixture of species.…”

“…[32,[69][70][71][72][73][74][75][76] Organoboride cocatalysts show unsatisfactory results in stability and anion coordination capacity, and they are rarely used as activators of the bis(arylimino)pyridine iron catalyst. [77][78][79][80][81] MAO is typically produced via controlled hydrolysis of trimethylaluminum (TMA), leading to a rather complex mixture of species. Besides, some residual TMA from the MAO (typically accounting for up to 1/3 of the total Al content) reduces the catalyst activity.…”