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In this work, we introduced a method for capturing aqueous drop based on a patterned substrate in space. Through the manipulation test of a colloidal drop, it could be verified that this patterned substrate had excellent control ability for aqueous drop in microgravity condition. The confinement mechanism of this substrate was clarified, which showed that drops with different volume could be pinned and attracted at a given area on the substrate. The confinement capability was related to the gravity effect, and the patterned substrate could confine aqueous drops with larger volume under microgravity than in normal gravity. With advantages of simple operation and strong capability to control large drops, this technique exhibited the wide application prospect in the fields of fluid management, biosensing, and pharmacy in microgravity condition in the future. [ABSTRACT FROM AUTHOR]

The article presents a science experiment to help college students measure the solution viscosity via diffusion-ordered nuclear magnetic resonance (NMR) spectroscopy. In this experiment, students explore the intermolecular forces including viscosity through numerous methods. Emphasis is on the investigation of the viscosity, a physical property based on molecular structure, using advanced NMR techniques.

The dimeric structure is characterized for a chiral amide base complex consisting of an (S)-N-isopropyl-O-triisopropylsilyl valinol ligand and lithium. The complex is characterized by a variety of NMR techniques, including multinuclear one- and two-dimensional NMR experiments and diffusion ordered NMR spectroscopy (DOSY) as well as diffusion coefficient-formula weight (D-fw) correlation analyses. Spartan calculations are presented which support the structural assignment. This structural characterization leads to an explanation of the behavior and the reactivity of these complexes in solution. [ABSTRACT FROM AUTHOR]

The tetrahydrofuran tetrasolvated dimeric lithium dienolate derived from 2,2,7,7-tetramethyloctan-3,6-dione is characterized in the solid state by X-ray diffraction analysis and in solution by diffusion NMR. This dienolate was reacted with tropanone to yield two new products that are also described. [ABSTRACT FROM AUTHOR]

The development of 6Li diffusion-ordered NMR spectroscopy (DOSY) is reported. This technique is applied to 6Li organometallic complexes. 6Li DOSY provides a facile means of identification of peaks in the 6Li spectrum, as well as evidence of mixed aggregates based on relative diffusion coefficients. 6Li data is correlated to 1H diffusion experiments through 6Li{1H} HOESY and/or 1H{6Li} HMBC experiments to obtain formula weight information of Li aggregates. [ABSTRACT FROM AUTHOR]

The development of 31P DOSY NMR with diffusion coefficient−formula weight (D-FW) analysis is reported. Commercially available trialkyl phosphine internal references were used in a model system to establish the molecular weight of a phosphorous containing organolithium compound. The feasibility of 31P DOSY D-FW studies is established. This extension of DOSY D-FW analysis expands its applicability to solution structure studies of a wide variety of compounds. [ABSTRACT FROM AUTHOR]