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The Industries need techniques for the rapid structure analysis of amino acid derivatives. The amino acid derivatives are sometimes produced as impurities in the industrial production processes, and cause toxicity problems. Herein, we report the crystalline sponge (CS) method analysis of variety of amino acids using a formyl group installed CS crystal. Most amino acids possess a primary amino group, which can form Schiff‐base with the formyl group under mild conditions. Thus, the formyl group installed CS crystal can efficiently capture the amino acids via Schiff‐base formation. We successfully analyzed derivatives of 18 proteogenic amino acids, 6 non‐proteogenic amino acids, and 4 dipeptides using the formyl group installed CS. We thus believe that the protocols shown in this study would serve the need of the industries. [ABSTRACT FROM AUTHOR]

Pd‐based molecular square Pd4L4 and triangle Pd3L3 represent the molecular ancestors of metal‐coordination polyhedra that have been an integral part of the field for the last 30 years. Conventional solution‐based reactions between cis‐protected Pd ions and 2,2′‐bipyridine exclusively give Pd4L4 and/or Pd3L3 as the sole products. We herein show that, under solvent‐free mechanochemical conditions, the self‐assembly energy landscape can be thermodynamically manipulated to form an elusive cyclic dimer Pd2L2 for the first time. In the absence of solvent, Pd2L2 is indefinitely stable in the solid‐state, but converts rapidly to its thermodynamic products Pd3L3 and Pd4L4 in solution, confirming Pd2L2 as a short‐lived kinetic species in the solution‐based self‐assembly process. Our results highlight how mechanochemistry grants access to a vastly different chemical space than available under conventional solution conditions. This provides a unique opportunity to isolate elusive species in self‐assembly processes that are too reactive to both "see" and "capture". [ABSTRACT FROM AUTHOR]

Pd‐based molecular square Pd4L4 and triangle Pd3L3 represent the molecular ancestors of metal‐coordination polyhedra that have been an integral part of the field for the last 30 years. Conventional solution‐based reactions between cis‐protected Pd ions and 2,2′‐bipyridine exclusively give Pd4L4 and/or Pd3L3 as the sole products. We herein show that, under solvent‐free mechanochemical conditions, the self‐assembly energy landscape can be thermodynamically manipulated to form an elusive cyclic dimer Pd2L2 for the first time. In the absence of solvent, Pd2L2 is indefinitely stable in the solid‐state, but converts rapidly to its thermodynamic products Pd3L3 and Pd4L4 in solution, confirming Pd2L2 as a short‐lived kinetic species in the solution‐based self‐assembly process. Our results highlight how mechanochemistry grants access to a vastly different chemical space than available under conventional solution conditions. This provides a unique opportunity to isolate elusive species in self‐assembly processes that are too reactive to both "see" and "capture". [ABSTRACT FROM AUTHOR]

Pd‐based molecular square Pd4L4 and triangle Pd3L3 represent the molecular ancestors of metal‐coordination polyhedra that have been an integral part of the field for the last 30 years. Conventional solution‐based reactions between cis‐protected Pd ions and 2,2′‐bipyridine exclusively give Pd4L4 and/or Pd3L3 as the sole products. We herein show that, under solvent‐free mechanochemical conditions, the self‐assembly energy landscape can be thermodynamically manipulated to form an elusive cyclic dimer Pd2L2 for the first time. In the absence of solvent, Pd2L2 is indefinitely stable in the solid‐state, but converts rapidly to its thermodynamic products Pd3L3 and Pd4L4 in solution, confirming Pd2L2 as a short‐lived kinetic species in the solution‐based self‐assembly process. Our results highlight how mechanochemistry grants access to a vastly different chemical space than available under conventional solution conditions. This provides a unique opportunity to isolate elusive species in self‐assembly processes that are too reactive to both "see" and "capture". [ABSTRACT FROM AUTHOR]

Pd‐based molecular square Pd4L4 and triangle Pd3L3 represent the molecular ancestors of metal‐coordination polyhedra that have been an integral part of the field for the last 30 years. Conventional solution‐based reactions between cis‐protected Pd ions and 2,2′‐bipyridine exclusively give Pd4L4 and/or Pd3L3 as the sole products. We herein show that, under solvent‐free mechanochemical conditions, the self‐assembly energy landscape can be thermodynamically manipulated to form an elusive cyclic dimer Pd2L2 for the first time. In the absence of solvent, Pd2L2 is indefinitely stable in the solid‐state, but converts rapidly to its thermodynamic products Pd3L3 and Pd4L4 in solution, confirming Pd2L2 as a short‐lived kinetic species in the solution‐based self‐assembly process. Our results highlight how mechanochemistry grants access to a vastly different chemical space than available under conventional solution conditions. This provides a unique opportunity to isolate elusive species in self‐assembly processes that are too reactive to both "see" and "capture". [ABSTRACT FROM AUTHOR]

The Industries need techniques for the rapid structure analysis of amino acid derivatives. The amino acid derivatives are sometimes produced as impurities in the industrial production processes, and cause toxicity problems. Herein, we report the crystalline sponge (CS) method analysis of variety of amino acids using a formyl group installed CS crystal. Most amino acids possess a primary amino group, which can form Schiff-base with the formyl group under mild conditions. Thus, the formyl group installed CS crystal can efficiently capture the amino acids via Schiff-base formation. We successfully analyzed derivatives of 18 proteogenic amino acids, 6 non-proteogenic amino acids, and 4 dipeptides using the formyl group installed CS. We thus believe that the protocols shown in this study would serve the need of the industries., (© 2023 Wiley-VCH GmbH.)

Due to the reversible nature of coordination bonds and solvation effect, coordination self-assembly pathways are often difficult to elucidate experimentally in solution, as intermediates and products are in constant equilibration. The present study shows that some of these transient and high-energy self-assembly intermediates can be accessed by means of ball-milling approaches. Among them, highly aqueous-unstable Pd 3 L1 1 and Pd 6 L1 4 open-cage intermediates of the framed Fujita Pd 6 L1 4 cage and Pd 2 L2 2 , Pd 3 L2 1 and Pd 4 L2 2 intermediates of Mukherjee Pd 6 L2 4 capsule are successfully trapped in solid-state, where Pd=tmedaPd 2+ , L1=2,4,6-tris(4-pyridyl)-1,3,5-triazine and L2=1,3,5-tris(1-imidazolyl)benzene). Their structures are assigned by a combination of solution-based characterization tools such as standard NMR spectroscopy, DOSY NMR, ESI-MS and X-ray diffraction. Collectively, these results highlight the opportunity of using mechanochemistry to access unique chemical space with vastly different reactivity compared to conventional solution-based supramolecular self-assembly reactions., (© 2023 Wiley-VCH GmbH.)

In this paper, we report the synthesis of a unique silicon(I)-based metalla-disilirane and report on its reactivity toward TMS-azide and benzophenone. Metal complexes containing disilylenes ((bis)silylenes with a Si-Si bond) are known, but direct ligation of the Si(I) centers to transition metals always generated dinuclear species. To overcome this problem, we targeted the formation of a mononuclear iron(0)-silicon(I)-based disilylene complex via templated synthesis, starting with ligation of two Si(II) centers to iron(II), followed by a two-step reduction. The DFT structure of the resulting η 2 -disilylene-iron complex reveals metal-to-silicon π-back donation and a delocalized three-center-two-electron (3c-2e) aromatic system. The Si(I)-Si(I) bond displays unusual but well-defined reactivity. With TMS-azide, both the initial azide adduct and the follow-up four-membered nitrene complex could be isolated. Reaction with benzophenone led to selective 1,4-addition into the Si-Si bond. This work reveals that selective reactions of Si(I)-Si(I) bonds are made possible by metal ligation.

Pd-based molecular square Pd 4 L 4 and triangle Pd 3 L 3 represent the molecular ancestors of metal-coordination polyhedra that have been an integral part of the field for the last 30 years. Conventional solution-based reactions between cis-protected Pd ions and 2,2'-bipyridine exclusively give Pd 4 L 4 and/or Pd 3 L 3 as the sole products. We herein show that, under solvent-free mechanochemical conditions, the self-assembly energy landscape can be thermodynamically manipulated to form an elusive cyclic dimer Pd 2 L 2 for the first time. In the absence of solvent, Pd 2 L 2 is indefinitely stable in the solid-state, but converts rapidly to its thermodynamic products Pd 3 L 3 and Pd 4 L 4 in solution, confirming Pd 2 L 2 as a short-lived kinetic species in the solution-based self-assembly process. Our results highlight how mechanochemistry grants access to a vastly different chemical space than available under conventional solution conditions. This provides a unique opportunity to isolate elusive species in self-assembly processes that are too reactive to both "see" and "capture"., (© 2022 Wiley-VCH GmbH.)

When chiral compounds with low enantiomeric excess (ee, R:S=m:n) were absorbed into the void of the crystalline sponge (CS), enantiomerically pure [(R) m (S) n ] chiral composites were formed, changing the centrosymmetric space group into non-centrosymmetric one. The absolute configuration of the analyte compounds was elucidated with a reasonable Flack (Parsons) parameter value. This phenomenon is characteristic to the "post-crystallization" in the pre-determined CS crystalline lattice, seldom found in common crystallization where the crystalline lattice is defined by an analyte itself. The results highlight the potential of the CS method for absolute configuration determination of low ee samples, an often encountered situation in asymmetric synthesis studies., (© 2021 Wiley-VCH GmbH.)