A robust and multifunctional cuboctahedral [In 36 (μ-OH) 24 (NO 3 ) 8 (Imtb) 24 ] MOF (In(Imtb)-MOF) with an atypical pyramidal nitrate ion-containing hitherto unknown SBU core [In 9 (μ-OH) 6 (NO 3 )] is reported. The intra-and interlayer nitrate ions adopt pyramidal and inverted pyramidal shapes, which separates the active indium site [(In 3 (μ-OH) 2 )NO 3 -(In 3 (μ-OH) 2 )] and linear In 3 (μ-OH) 2 by 0.5 and 0.9 nm, respectively. Additionally, the high density of active metal sites shows remarkable catalytic activity with higher TOF even for sterically hindered substrates in Strecker synthesis and CO 2 cycloaddition. Moreover, the luminescence behavior of In(Imtb)-MOF and the presence of uncoordinated nitrogen atoms are exploited for selective sensing of explosive trinitrophenol (TNP) with a detection limit (LOD) of 2.3 ppb.

Developing an economical and robust sensor using an earth-abundant metal-based metal–organic framework (MOF) to detect trace water content rapidly is crucial for laboratories and chemical industries. Herein, a mixed-valent chiral [{Cu+Cu3 2+(2,4-Imdb)3(H2O)3}·Cl]∞ MOF manifests atypical quantitative detection of a trace amount of water [0.016% (v/v)] in organic solvents. Single-crystal X-ray diffraction and time-correlated single-photon counting supported the mechanism for turn-on fluorescence.

The deprotonation of acyclic palladium amidine chloride (1) with potassium tert-butoxide in tetrahydrofuran results in palladium bis(formamidinate) (2). 2 undergoes a nucleophilic addition reaction with acetonitrile in the presence of PdCl 2 or Pd(OAc) 2 (OAc = acetate) to give dinuclear cyclic six-membered (triazapentadiene)palladium complexes (4a and 4b). These compounds are also prepared from cyclic six-membered (tap)PdCl 2 (5; tap = triazapentadiene) or formamidinium salts (6a−6c) with Pd(OAc) 2 /NaOAc in acetonitrile, whereas the direct reaction of 2 with acetonitrile or acrylonitrile resulted in palladium black or an acyclic C−N-coupled product (3). A comparison of structure 4 from 2 suggests a possible intermediate dinuclear palladium complex whose structure was identified through theoretical calculations. Further, Suzuki−Miyaura cross-coupling reactions were carried out under different solvents notably in an ethanol/water medium at room temperature.

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The majority of the copper N-heterocyclic carbene (NHC) complexes contain Cu in a + 1 oxidation state. The Cu(II)-NHC complexes reported so far usually require strict inert atmosphere conditions. In this work, we report a very facile and quantitative preparation of a series of new Cu(II)-NHC complexes ( 2a-c) starting from the inexpensive and readily available Cu(II) salts like Cu(OAc) 2 and CuCl 2 • 2H 2 O with imidazolium salts (1 a-c), wherein 2 b and 2 c were exclusively synthesized in water under aerobic condition. It should be emphasized that this is the first example where Cu(II)-NHC complexes have been prepared in the aqueous medium. All the complexes have manifested with a heterobidentate C, O chelate type of coordination to Cu(II) centers forming trans-[Cu(IRpyO) 2 ] (where R = Me, Mes, Dipp) type of complexes where 2 b forms a perfect square planar Cu(II)-NHC complex. Complexes 2 a-c were evaluated as catalysts for the aerobic oxidation of alcohols.