A highly ordered homochiral nanotubular crystalline framework was assembled from a hexameric Zn6L6metallaycle that was built from metallosalen ZnL units (H2L = (R,R)-(-)-N,N'-Bis(3-tert-butyl-5-(4- pyridyl) salicylidene)-1,2-diaminocyclohexane) by the complementary coordination of the pyridyl groups to the metal centers. Chiral channels and hydrophobic functionality presented by this structure make it an excellent host to recognize and separate racemic alcohols with high enantioselectivity (up to 99.5%). The crystalline solid can be easily recycled and reused five times without loss of crystallinity and enantioselectivity.

Over the past decade, supramolecular compounds with organometallic Ir, Rh, Ru based half-sandwich complexes have received considerable attention as materials with a variety of potential applications. The major emphasis of this tutorial review lies on the self-assembly of such organometallic half-sandwich molecular rectangles, prisms and cages with half-sandwich corners and two different rigid bifunctional ligands using an approach of stepwise construction. Synthetic methods and the structural and functional properties of the target complexes are discussed in detail.

Coordination-driven self-assembly provides unique opportunities to design and prepare ordered arrays of molecules and clusters, and has led to significant progress in the construction of metal-organic assemblies with potentially exploitable functions, from ion exchange to gas storage to separations to catalysis. [1, 2] Of particular interest to us are elegant works on coordination-linked porphyrin arrays that demonstrate the feasibility of constructing a large family of meso-metalloporphyrin cycles and boxes based on complementary coordination interactions between coordinatively unsaturated central metal atoms and coordinating sidearms.[3] This assembling process is especially effective for the construction of discrete cyclic arrays, in that appropriately designed components are almost automatically self-assembled to form large arrays, thus providing an associated entropic advantage.[3c] However, such a direct approach has thus far received less attention in other supramolecular systems. [4,5] Metallosalen-based architectures (salen = N,N'-ethylenebis(salicylideneaminato)) have diverse potential applications in catalysis and separations, [6, 7] which motivated us to examine the self-assembly of enantiopure complementary metallosalen complexes through coordination, with the aim of generating well-defined enzyme-like chiral cavities and functionalities for enantioselective processes. With a few notable exceptions, metal-organic assemblies have not been explored for chirotechnology. [8, 9] Herein, we report the efficient self-assembly of a chiral porous macromolecule from the semiflexible pyridyl-functionalized metallosalen [ZnL] using coordination bonds (Figure 1).[6a] Single crystals of the robust metallomacrocycle show a reversibly and controllably dynamic behavior induced by external stimuli, and remarkably, can be used to separate small racemic alcohols with an enantioselectivity of up to 99.8 % ee.Heating Zn(NO 3 ) 2 ·6 H 2 O and H 2 L (1:1) in a mixture of DMF and CH 3 CN afforded light-yellow, rod-like crystals in high yield. The product is stable in air and insoluble in water and common organic solvents, and was formulated as [Zn 4 L 4 ]·4 CH 3 CN (1·4 CH 3 CN) on the basis of elemental analysis, IR spectroscopy, and thermogravimetric analysis (TGA).A single-crystal X-ray diffraction study performed on 1·4 CH 3 CN reveals a metallomacrocycle constructed from four [ZnL] molecules by the complementary coordination of the pyridyl groups to the metal centers (Figure 1).[10] Compound 1·4 CH 3 CN crystallizes in the tetragonal chiral space group P4 2 , with a crystallographic C 2 axis passing through the center; thus, half of the tetramer is in the asymmetric unit. Each Zn center adopts a square-pyramidal geometry with the

Background: Fatty infiltration of the rotator cuff muscles is highly related to poor outcomes after rotator cuff tears. Fat fraction (FF) based on traditional 2–dimensional measurements (2D-FF) from a single sagittal Y-view slice cannot determine intramuscular FF in the rotator cuff muscles; the newly developed 3–dimensional method (3D-FF) is supposed to precede 2D measurements for intramuscular FF evaluation in accuracy and reliability. Purpose: (1) To measure 3D-FF and (2) to compare 3D-FF and 2D-FF in terms of quantitative values and intra- and interobserver agreement. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: Six-point Dixon magnetic resonance imaging was performed in patients with full–thickness supraspinatus tears. 2D-FF was calculated on a single sagittal Y-view. Semiautomatic segmentation software (ITK-SNAP) was used to reconstruct 3D volumes of the supraspinatus muscle and fat. 3D-FF was obtained by dividing the fat volume by the total volume of the supraspinatus muscle. A paired t test was used to compare the individual differences between 2D-FF and 3D-FF results. Linear regression and Bland-Altman analyses were performed to determine the agreement between 2D-FF and 3D-FF. Intraclass correlation coefficients (ICCs) were calculated to determine intra- and interobserver agreement. Results: The 3D muscular and fatty models presented an inhomogeneous distribution of intramuscular fat in the supraspinatus, indicating the superiority of 3D-FF over 2D-FF in capturing all muscle morphologic information. 2D-FF was significantly higher than 3D-FF in the supraspinatus with large (19.5% ± 5.9% vs 16.2% ± 3.7%; P = .002) and massive (34.8% ± 13.3% vs 26.2% ± 9.4%; P < .001) rotator cuff tears. 2D-FF overestimated the FF compared with 3D-FF by >50% in 14.7% of all patients and by >15% in 67.6% of patients with large or massive RCTs. The discrepancy between 2D-FF and 3D-FF increased with increasing mean FF. The intra- and interobserver agreement of 3D-FF (ICCs, 0.89-0.99 and 0.89-0.95) was superior to that of 2D-FF (ICCs, 0.71-0.95 and 0.64-0.79). Conclusion: 3D-FF indicated an inhomogeneous distribution of intramuscular fat by capturing all muscle and fat morphologic information. In patients with large and massive rotator cuff tears, 2D-FF of the supraspinatus was significantly higher than 3D-FF. 3D-FF was more reliable than 2D-FF for estimating fatty infiltration in the supraspinatus, with better intra- and interobserver agreement.