The tetraazido dinuclear Cu(II) complexes 1 and 2 of the polyaza-polyoxa macrocyclic ligands 4, [24]ane-N2Oe, and 5, [24]ane-N602, respectively, have been prepared, and their crystal structures have been determined. In both cases the two copper ions are contained inside the molecular cavity and are bound to the ONO and NNN chelating subunits situated at the two poles of the macrocycles 4 and 5, respectively. 1 crystallizes in the monoclinic system, space group P2\/n (a = Dihedral Angles N(l)-C(2)-C(3)-0(4) 59.6 C(2)-C(3)-0(4)-C(5) -165.6 C(3)-0(4)-C(5)-C(6) 178.9 0(4)-C(5)-C(6)-0(7) 65.3 C(5)-C(6)-0(7)-C(8) -167.1 C(6)-0(7)-C(8)-C(9) 158.9 O(7)-C(8)-C(9)-O(10) -69.4 C(8)-C(9)-O(10)-C(U) 179.9 C(9)-O(10)-C(ll)-C(12) -179.3 O(10)-C(ll)-C(12)-N(13) -59.8 C(ll)-C(12)-N(13)-C(14) -166.6 C(12)-N(13)-C(14)-C(15) 175.1 N(13)-C(14)-C(15)-0(16) 61.4 C(14)-C(15)-0(16)-C(17) -176.2 C(15)-0(16)-C(17)-C(18) 169.1 0(16)-C( 17)-C( 18)-0(19)64.8 C(17)-C(18)-O(19)-C(20) -174.0 C(18)-O(19)-C(20)-C(21) 170.2
The tritopic hexa-aza-macrocycle (1) binds three Cull ions in solution and leads in particular to the assembly of a trinuclear bis-p3-hydroxo bridged complex whose crystal structure has been determined; it may be considered as a cryptate of a cationic cluster [ C U ~( O H ) ~] ~+ held inside the macrocyclic cavity of the ligand.
The stability constants of the hydroxide complexes of zirconium(IV) and uranium(IV) have been measured at 15, 25 and 35ºC [in 1.0 mol dm -3 (Na, H)ClO 4 ] using potentiometry. For zirconium(IV), the results indicate the presence of Zr(OH) 3+ and the polymeric species Zr 3 (OH) 4 8+ and Zr 4 (OH) 8 8+ whereas the results for uranium(IV) indicate the presence of U(OH) 3+ and the polymeric species U 4 (OH) 12
4+. The hydrolysis of both metal ions was studied at three temperatures allowing the determination of ∆Hº and ∆Sº of reaction for each species. The results were compared with previous results determined for thorium(IV) under the same experimental conditions to ascertain whether thorium should be used as an analogue for other tetravalent metal ions in safety assessment studies of nuclear repositories.
The synthesis of nine macrocyclic polyamines 2-10 containing pyridine units is described. These compounds are 22-(9), 24-(24,6,8, lo), or 26-(5.7) membered hexaaza (2,3,9,10) or octaaza (4-7) macrocycles in which one to four pyridine units are incorporated. Compounds 3,4,9, and 10 are homoditopic ligands, whereas 2 and 5 are heteroditopic and 6-8 multitopic receptors. Compounds 2-10 are potential ligands for metal cations as well as, in their protonated forms, for anions. Protonated macrocycles 2-10 are also potential catalysts for the hydrolysis of nucleotides and polyphosphates.
Die makrocyclischen Cu(II)‐Komplexe (I) und (II) werden durch die Umsetzung von Cu(II)‐perchlorathexahydrat mit den Makrocyclen in Methanol und nachfolgender Metathesereaktionen der entstehenden Perchlorate mit Na‐azid dargestellt (keine Ausb.‐Angaben).
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