Crystal Structures of the [2.2.2]Cryptates [Cd(cryptand 222)][CdCl4] and [Hg(cryptand 222)][Hg2Cl6] with 8-Coordinated Metal Ions

Reactions of [2.2.2]cryptand, 4,7,13,16,21,24-Hexaoxa-1,10-diazabicyclo-[8.8.8]hexacosane, (“cryptand 222”) with cadmium chloride and mercuric chloride yielded crystals of [Cd(cryptand 222)][CdCl4] (1) and [Hg(cryptand 222)][Hg2Cl6] (2). 1 crystallizes tetragonally, space group P42/n, Z = 4, a = 1239.8(2), c = 1801.2(8) pm; 2 is monoclinic, space group P2/n, Z = 2, a = 1060.3(3), b = 955.2(2), c = 1607.0(3) pm. and β = 108.85(2)°. In the cations of both complexes the metal ions are enclosed in the bicyclic ligand and show 8-coordination to its six oxygen and two nitrogen atoms, the coordination polyhedron is a distorted cube for 1 and a bicapped trigonal antiprism for 2. The anion of 2 is dimeric, the two mercury atoms are connected via chlorine bridges with Hg-Cl distances of 258 and 278 pm, the Hg-Cl bond lengths to the two terminal chloro ligands being shorter at 236 and 238 pm

Crystal Structures of Two Copper(II) Cyclam Complexes: [{CuCl(C10N4H24 )}2][CdCl4] and [Cu(C10N4H24)][CdCl3 (H2O)2]Cl

Crystals of both complexes were obtained by evaporation of the ethanol solvent. The crystals of [{CuCl(C10N4H24)}2][CdCl4] are tetragonal, space group I4̄2d, Z = 4, a = b = 1784.1(11), c = 1101.1(8) pm. Each copper atom is bonded to one cyclam ligand and two chlorine atoms which are acting as bridging ligands and connect the copper atoms to chains of distorted octahedra. Distorted tetrahedra of CdCl4 are situated in cavities between these chains. The crystals of [Cu(C10N4H24)][CdCl3(H2O)2]Cl are monoclinic (b), space group C2/c, Z = 4, a = 1581.9(8), b = 1323.3(7), c = 924.0(5) pm, β = 94.31(5)°. Cadmium is coordinated to four chlorine atoms and two water molecules, while all of the chlorine atoms act as bridging ligands connecting every cadmium atom to two adjacent cadmium atoms and to two copper atoms which lie in plane with the N atoms

The Crystal Structure of Hexa-μ-chloro-μ4- oxo-tetrakis [hexamethylenetetraminecopper- (II)], [Cu4Cl6O(C6H12N4)4], a Copper(II) Complex with a Structure Related to that of Beryllium Oxoacetate

By reaction of solutions of CuCl2·2H2O and hexamethylenetetramine, C6H12N4, in acetone, a complex [Cu4Cl6O(C6H12N4)] could be obtained as single crystals. An X-ray analysis shows that the complex has a structure related to that of basic beryllium acetate. An oxygen atom is tetrahedrally surrounded by four cop-per atoms which, together with six chlorine atoms, form an adamantane-like core. Each copper atom is bonded via a nitrogen atom to a hexamethylenetetramine molecule

Molecular and Crystal Structure of l,r-Dimethylsilylene Titanocene Dichloride, (CH3)2Si(C5H4)2TiCl2

The molecular structure of the bridged [1]-titanocenophane 1,1'-dimethylsilylene titanocene dichloride, (CH3)2Si(C5H4)2TiCl2, has been investigated by an X-ray structure determination. Crystal data: monoclinic, space group C2/c, Z = 4, a = 1332.9(3), 6 = 988.7(3), c = 1068.9(3) pm, β = 113.43(2)°. The results are compared with the structural dimensions of similar compounds: 1,1'-methylene titanocene dichloride, CH2(C5H4)TiCl2, with the unbridged titanocene dichloride, (C5H5)2TiCl2 and the ethylene-bridged compound (CH2)2(C5H4)2TiCl2

Thyroxine-binding globulin: investigation of microheterogeneity

Preparations of T4-binding globulin (TBG) from human serum was performed using only two affinity chromatography steps. Purity of the protein was demonstrated by a single band in overloaded disc and sodium dodecyl sulfate electrophoresis, equimolar binding to T4, and linearity in sedimentation velocity run. The molecular weight was calculated to be 60,000 +/- 3,000 daltons (n = 3), the sedimentation coefficient was 3.95S, and the Stokes' radius was 37 A. The amino acid composition was found to be in good agreement with the calculations of other authors. By isoelectric focussing (IEF), pure TBG showed four main bands at pH 4.25, 4.35, 4.45, and 4.55 together with several fainter bands. The N- acetylneuraminic acid (NANA) content of the four TBG bands isolated by preparative IEF was found to decrease from 10.2 mol NANA/mol TBG in the band at pH 4.25 to 4.8 mol NANA/mol TBG in the band at pH 4.55. No significant difference in the affinity constants of the TBG bands to T4 was found. The affinity constants for TBG ranged from 3.1 x 10(9) to 7.2 x 10(9) M-1. Sequential kinetic desialylation of pure TBG resulted in a progressive tendency toward one major band at pH 6.0. In native sera, microheterogeneity of TBG was detected after IEF on polyacrylamide gel plates by immunofixation. The typical TBG patterns shown by pure TBG were also found in normal subjects. Characteristic deviations from this pattern were found in the sera of females during estrogen therapy or pregnancy, where there was a gradual increase in density of the band at pH 4.25 and the appearance of an additional band at pH 4.15. In sera from patients with liver disease and elevated TBG levels, there was a fading of the acidic bands, whereas the more alkaline band at pH 4.55 was intensified. It is therefore proposed that microheterogeneity of TBG is caused by differences in NANA content and that variations of TBG patterns in native sera may reflect altered TBG synthesis or degradation. A genetically related microheterogeneity of TBG could not be demonstrated after examination of 800 sera, including 2 families with quantitative TBG deficiency