No abstract

In the title compound, [Cu2(C7H5O2)4(C10H9N)2], the paddle-wheel-type dinuclear complex is constructed by four bridging benzoate groups and two terminal 6-methyl­quinoline ligands. The asymmetric unit contains one-half of the whole mol­ecule, and there is an inversion center at the mid-point of the Cu⋯Cu bond. The octa­hedral coordination of each Cu atom, with four O atoms in the equatorial plane, is completed by the N atom of the 6-methyl­quinoline mol­ecule [Cu—N = 2.212 (2) Å] and by another Cu atom [Cu⋯Cu = 2.6939 (13) Å]. The Cu atom lies 0.234 Å out of the plane of the four O atoms. The molecular packing is stabilized by one intramolecular C—H⋯O as well as C—H⋯π and π–π interactions.

ObjectiveTo compare the lumbar vertebral bone marrow fat-signal fractions obtained from six-echo modified Dixon sequence (6-echo m-Dixon) with those from single-voxel magnetic resonance spectroscopy (MRS) in patients with low back pain.Materials and MethodsVertebral bone marrow fat-signal fractions were quantified by 6-echo m-Dixon (repetition time [TR] = 7.2 ms, echo time (TE) = 1.21 ms, echo spacing = 1.1 ms, total imaging time = 50 seconds) and single-voxel MRS measurements in 25 targets (23 normal bone marrows, two focal lesions) from 24 patients. The point-resolved spectroscopy sequence was used for localized single-voxel MRS (TR = 3000 ms, TE = 35 ms, total scan time = 1 minute 42 seconds). A 2 × 2 × 1.5 cm3 voxel was placed within the normal L2 or L3 vertebral body, or other lesions including a compression fracture or metastasis. The bone marrow fat spectrum was characterized on the basis of the magnitude of measurable fat peaks and a priori knowledge of the chemical structure of triglycerides. The imaging-based fat-signal fraction results were then compared to the MRS-based results.ResultsThere was a strong correlation between m-Dixon and MRS-based fat-signal fractions (slope = 0.86, R2 = 0.88, p < 0.001). In Bland-Altman analysis, 92.0% (23/25) of the data points were within the limits of agreement. Bland-Altman plots revealed a slight but systematic error in the m-Dixon based fat-signal fraction, which showed a prevailing overestimation of small fat-signal fractions (< 20%) and underestimation of high fat-signal fractions (> 20%).ConclusionGiven its excellent agreement with single-voxel-MRS, 6-echo m-Dixon can be used for visual and quantitative evaluation of vertebral bone marrow fat in daily practice.

The title compound, [Zn(C8H6O3)2(C12H12N2)]n, consists of [Zn(Hopa)2] (H2opa = 2-hydr­oxy-2-phenyl­acetic acid or mandelic acid) units bridged by 1,2-di-4-pyridylethane (bpe) ligands, forming a polymeric chain developing parallel to the b axis. The bridging bpe ligand is arranged around a twofold axis passing through the middle of the ethane C—C bond. The geometry around the ZnII ion is distorted octa­hedral, constructed by four O atoms from two Hopa− ligands and two N atoms from two bridging bpe ligands. O—H⋯O hydrogen bonds link the chains, forming a three-dimensional network.

The central part of the title centrosymmetric dinuclear complex, [Zn2(C7H5O2)4(C9H12N2)2], has a paddle-wheel conformation with four benzoate ligands bridging two symmetry-related ZnII ions. The distorted square-pyramidal coordination environment around the ZnII ion is completed by an N atom from a 4-(pyrrolidin-1-yl)pyridine ligand. The Zn⋯Zn separation of 2.9826 (12) Å does not represent a formal direct metal–metal bond. The ZnII ion is displaced by 0.381 (1) Å from the mean plane of the four basal O atoms. Two of the C atoms of the pyrrolidine ring are disordered over two sites with refined occupancies of 0.53 (2) and 0.47 (2).