Structural diversity in alkali metal and alkali metal magnesiate chemistry of the bulky 2,6-diisopropyl-N-(trimethylsilyl)anilino ligand

Bulky amido ligands are precious in s-block chemistry since they can implant complementary strong basic and weak nucleophilic properties within compounds. Recent work has shown the pivotal importance of the base structure with enhancement of basicity and extraordinary regioselectivities possible for cyclic alkali metal magnesiates containing mixed n-butyl/amido ligand sets. This work advances alkali metal and alkali metal magnesiate chemistry of the bulky aryl-silyl amido ligand [N(SiMe3)(Dipp)] (Dipp = 2,6-iPr2-C6H3). Infinite chain structures of the parent sodium and potassium amides are disclosed, adding to the few known crystallographically characterised unsolvated s-block metal amides. Solvation by PMDETA or TMEDA gives molecular variants of the lithium and sodium amides; whereas for potassium, PMDETA gives a molecular structure but TMEDA affords a novel, hemi-solvated infinite chain. Crystal structures of the first magnesiate examples of this amide in [MMg{N(SiMe3)(Dipp)}2(μ-nBu)]∞ (M = Na or K), are also revealed though these breakdown to their homometallic components in donor solvent as revealed through NMR and DOSY studies

Circadian regulation of hormone signaling and plant physiology

The survival and reproduction of plants depend on their ability to cope with a wide range of daily and seasonal environmental fluctuations during their life cycle. Phytohormones are plant growth regulators that are involved in almost every aspect of growth and development as well as plant adaptation to myriad abiotic and biotic conditions. The circadian clock, an endogenous and cell-autonomous biological timekeeper that produces rhythmic outputs with close to 24-h rhythms, provides an adaptive advantage by synchronizing plant physiological and metabolic processes to the external environment. The circadian clock regulates phytohormone biosynthesis and signaling pathways to generate daily rhythms in hormone activity that fine-tune a range of plant processes, enhancing adaptation to local conditions. This review explores our current understanding of the interplay between the circadian clock and hormone signaling pathways