“…Previously, similar disorder has often been described simply by two partially occupied sulfur positions assuming inversion of the DMSO ligand. The overlapping non-resolved atomic positions result in high displacement parameters of the other ligand atoms, while the disorder model employed in this study resolves all the atomic sites. 1 Octakis(DMSO)lanthanum(III) complex at 100 K in the [La(OS(CH 3 ) 2 ) 8 ]I 3 crystal structure with 40% probability ellipsoids.…”
The octakis(DMSO) (DMSO = dimethylsulfoxide) neodymium(III), samarium(III), gadolinium(III), dysprosium(III), erbium(III), and lutetium(III) iodides crystallize in the monoclinic space group P21/n (No. 14) with Z = 4, while the octakis(DMSO) iodides of the larger lanthanum(III), cerium(III), and praseodymium(III) ions crystallize in the orthorhombic space group Pbca (No. 61), Z = 8. In all [Ln(OS(Me2)8]I3 compounds the lanthanoid(III) ions coordinate eight DMSO oxygen atoms in a distorted square antiprism. Up to three of the DMSO ligands were found to be disordered and were described by two alternative configurations related by a twist around the metal-oxygen (Ln-O) bond. To resolve the atomic positions and achieve reliable Ln-O bond distances, complete semirigid DMSO molecules with restrained geometry and partial occupancy were refined for the alternative sites. This disorder model was also applied on previously collected data for the monoclinic octakis(DMSO)yttrium(III) iodide. At ambient temperature, the eight Ln-O bond distances are distributed over a range of about 0.1 A. The average value increases from Ln-O 2.30, 2.34, 2.34, 2.36, 2.38, 2.40 to 2.43 A (Ln = Lu, Er, Y, Dy, Gd, Sm, and Nd) for the monoclinic [Ln(OSMe2)8]I3 structures, and from 2.44, 2.47 to 2.49 A (Ln = Pr, Ce, and La) for the orthorhombic structures, respectively. The average of the La-O and Nd-O bond distances remained unchanged at 100 K, 2.49 and 2.43 A, respectively. Despite longer bond distances and larger Ln-O-S angles, the cell volumes are smaller for the orthorhombic structures (Ln = Pr, Ce, and La) than for the monoclinic structure with Ln = Nd, showing a more efficient packing arrangement. Raman and IR absorption spectra for the [Ln(OS(CH3)2)8]I3 (Ln = La, Ce, Pr, Nd, Gd, Tb, Dy, Er, Lu, and Y) compounds, also deuterated for La and Y, have been recorded and analyzed by means of normal coordinate methods. The force constants for the Ln-O and S-O stretching modes in the complexes increase with decreasing Ln-O bond distance and show increasing polarization of the bonds for the smaller and heavier lanthanoid(III) ions.
“…Previously, similar disorder has often been described simply by two partially occupied sulfur positions assuming inversion of the DMSO ligand. The overlapping non-resolved atomic positions result in high displacement parameters of the other ligand atoms, while the disorder model employed in this study resolves all the atomic sites. 1 Octakis(DMSO)lanthanum(III) complex at 100 K in the [La(OS(CH 3 ) 2 ) 8 ]I 3 crystal structure with 40% probability ellipsoids.…”
The octakis(DMSO) (DMSO = dimethylsulfoxide) neodymium(III), samarium(III), gadolinium(III), dysprosium(III), erbium(III), and lutetium(III) iodides crystallize in the monoclinic space group P21/n (No. 14) with Z = 4, while the octakis(DMSO) iodides of the larger lanthanum(III), cerium(III), and praseodymium(III) ions crystallize in the orthorhombic space group Pbca (No. 61), Z = 8. In all [Ln(OS(Me2)8]I3 compounds the lanthanoid(III) ions coordinate eight DMSO oxygen atoms in a distorted square antiprism. Up to three of the DMSO ligands were found to be disordered and were described by two alternative configurations related by a twist around the metal-oxygen (Ln-O) bond. To resolve the atomic positions and achieve reliable Ln-O bond distances, complete semirigid DMSO molecules with restrained geometry and partial occupancy were refined for the alternative sites. This disorder model was also applied on previously collected data for the monoclinic octakis(DMSO)yttrium(III) iodide. At ambient temperature, the eight Ln-O bond distances are distributed over a range of about 0.1 A. The average value increases from Ln-O 2.30, 2.34, 2.34, 2.36, 2.38, 2.40 to 2.43 A (Ln = Lu, Er, Y, Dy, Gd, Sm, and Nd) for the monoclinic [Ln(OSMe2)8]I3 structures, and from 2.44, 2.47 to 2.49 A (Ln = Pr, Ce, and La) for the orthorhombic structures, respectively. The average of the La-O and Nd-O bond distances remained unchanged at 100 K, 2.49 and 2.43 A, respectively. Despite longer bond distances and larger Ln-O-S angles, the cell volumes are smaller for the orthorhombic structures (Ln = Pr, Ce, and La) than for the monoclinic structure with Ln = Nd, showing a more efficient packing arrangement. Raman and IR absorption spectra for the [Ln(OS(CH3)2)8]I3 (Ln = La, Ce, Pr, Nd, Gd, Tb, Dy, Er, Lu, and Y) compounds, also deuterated for La and Y, have been recorded and analyzed by means of normal coordinate methods. The force constants for the Ln-O and S-O stretching modes in the complexes increase with decreasing Ln-O bond distance and show increasing polarization of the bonds for the smaller and heavier lanthanoid(III) ions.
“…For group 2 in particular, considerable effort was expended in attempting to provide characterisation as complete as that presented previously for the group 1 complexes but crystals appropriate for structure determinations were obtained with Ca and Ba only. [59] (130 mg) in dmf (1 mL) was mixed with a solution formed by adding (LH 4 ·CHCl 3 ) (100 mg) and N(CH 2 CH 3 ) 3 (0.1 mL) to dmf (1 mL). The initially clear solution was allowed stand for 2 d as colourless plate-like crystals deposited.…”
Section: Methodsmentioning
confidence: 99%
“…The coordination environment about the barium has quasi-2 symmetry; the intervening sulfur atoms also may again be considered to interact as shown in Figure 4, so that the ligands again bind as OSO fac-tripods, this time remarkably symmetrically [ Table S4, (a)]. The longer bonds and higher coordination number expected for Ba II relative to Ca II [59] are presumably some of the factors causing this complex to adopt a structure ( Figure 4) better described as derived from a "stepped" and not bent, ditopic receptor. As in the ligands of the calcium compounds (Table S1) columns is 20.625(5) Å.…”
In extension of previous work involving structural characterisation of complex salts formed between main group 1 metal ions and p‐tert‐butyltetrathiacalixarene, LH4, the present study encompasses complexes with a wider array of main group 2, 13, 14 metal ions. For group 2, single‐crystal X‐ray structural characterisation of Ca(LH3)2·3dmf (1a), {Ca(LH2)·3dmf}2 (1b), Ba(LH3)2·6dmf (2a) and BaCO3·3Ba(LH3)2·3H2O·3CH3CN·12.25CH2Cl2 (2b) provides models for various coordination units. For group 13, this applies to {Ga(OH)(LH2)·3.5dmf}2 (3), {In(LH)·4EtOH·2CH2Cl2}2 (4a) and {In(OH)(LH2)·3CH2Cl2}4 (4b), and for group 14, to OPb4(LH)2·6dmf·dmso·2H2O (5). Overall, these define mononuclear (1a, 2a), binuclear (1b, 3, 4b) and tetranuclear (2b, 4b, 5) species. The calixarene cavities frequently include solvent molecules, though this capacity is clearly influenced by the nature of the bound metal ion(s) and their binding, as well as the associated impact on the conformation of the calixarene ligand(s).
“…Structures of the present and many related complexes of DMSO [2][3][4]12,21,38] do have a general value, however, in defining some of the consequences of the action of attractive, as distinct from repulsive or 'steric' forces between ligands on the form of their complexes, especially as there is no reason to expect that such effects should be limited to DMSO [39]. Further, evidence that solution and solid-state structures of solvento complexes are commonly identical [12] means that these attractions may be determinants of solution properties as well as those of solids.…”
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