Rabbit Anti-Human Cullin 2 monoclonal antibody, clone 60I28M23

The chemical mutability of metal-organic frameworks (MOFs) is an advantageous feature that allows fine-tuning of their physical and chemical properties. Herein, we report the successful isoreticulation of a MOF with an outstanding gas selectivity for CO2 versus N-2: [Cu(L1)(H2O)]center dot xS (CuL1), where H(2)L1 = bis(4-(4-carboxyphenyl)-1H-pyrazolyl) methane) and S = solvate. By modifying the steric bulk and length of the original ligand, we synthesised three new MOFs with 2D networks isoreticular to CuL1, namely [Cu(L1Me)(H2O)]center dot xS (CuL1Me), [Cu(L2)(H2O)]center dot xS (CuL2), and [Cu(L2Me)(H2O)]center dot xS (CuL2Me) (where H(2)L1Me = bis(4-(4-carboxyphenyl)-3,5-dimethyl-1H-pyrazolyl)methane, H(2)L2 = bis(4-(4-carboxyphenyl)-(ethyne-2,1-yl)-1H-pyrazolyl) methane, and H(2)L2Me = bis(4-(4-carboxyphenyl)( ethyne-2,1-yl)-3,5-dimethyl-1H-pyrazolyl) methane). Depending on the steric hindrance and structure metrics of the organic links, staggered and eclipsed arrangements of 2D 4(4) net layers were obtained. The anisotropy of the pore dimensions is proportional to the linker length (L2 and L2Me), which when increased, renders these materials nonporous. However, the more sterically demanding ligand L1Me gives a material that shows gate-opening behaviour in response to a CO2 absorbate. The synthesis and structure of an unexpected mixed-valence Cu-II/Cu-I 3D MOF, Cu-3[Cu(L2Me)(2)](2)(H2O)(4)]center dot xS (Cu-5(L2Me)(4)), containing an unusual trimeric Cu-II node are also reported.

The work in this paper presents the syntheses, characterization, crystal structures and magnetic properties of bis(end-on azide) bridged dicopper(II) complexes [(CuL1)-L-II(mu(1.1)-N-3)] (1), [(CuL2)-L-II(mu(1.1)-N-3)] (2) and [(CuL3)-L-II(mu(1.1)-N-3)]center dot MeOH (3), where HL1, HL2 and HL3 are half-condensed ligands produced from, respectively, 3-ethoxysalicylaldehyde and ethylenediamine, salicylaldehyde and trans-1,2-diaminocyclohexane, and 3-methoxysalicylaldehyde and trans-1,2-diaminocyclohexane. While compound 1 crystallizes in the monoclinic crystal system and P2(1)/c space group, the crystal system and space group for 2 and 3 are triclinic and P (1) over bar. There are two independent units, Unit-I and Unit-II, in 3. Each metal center in 1-3 is pentacoordinated and adopts a distorted square pyramidal coordination geometry. Each of the two bridging azide nitrogen atoms occupies an equatorial position of one copper(II) center, but the axial position of the second metal center. The Cu-N-3-Cu bridge angle in 1,2 and Unit-II of 3 lie in the range 87.8-90.8 degrees, while Unit-I in 3 displays a Cu-N-3-Cu angle of 84.3 degrees, which is the smallest bridge angle observed so far in end-on azide bridged dicopper(II) systems. Variable-temperature (2-300 K) magnetic studies reveal weak antiferromagnetic interactions in 1-3 with J values (H = -JS(1)S(2)) of -10.16, -4.18 and -1.43 cm(-1), respectively. (C) 2013 Elsevier Ltd. All rights reserved.