Dinuclear macrocycle

Figure 4. Representation of the host-guest geometry of dinuclear macrocycle, an analogue of 13, in the crystal structure of coordination polymer, 19.

Figure 7 A dinuclear macrocycle reorganizes into a quadruple-stranded helicate in the presence of hexafluorophosphate anion (represented by a sphere). ...

It should be noted that 02 binding mode, stability, reversibility and oxygnation activity strongly depend on ligand properties. In order to bind O2 geometrical constraints seem to be most important and a dinuclear (macrocyclic) copper system is not required. 

It is noteworthy that sodium 2,6-diformyl-4-methylphenolate reacts easily with 1,3-diaminopropane, leading to a 2 -t- 2 macrocycUc Schiff base isolated as its disodium complex [26]. The latter undergoes transmetallation by transition metals to yield dinuclear macrocyclic complexes [27]. 

Lin C-X, KongX-F, Xn F-B, Zhang Z-Z, Yuan F. Dinuclear macrocyclic qninohne bridged mercnry and silver bis(N-heterocychc carbene) complexes synthesis, stmcture and spectroscopic smdies. Z Anorg Allg Chem. 2013 639 881-885. 

From 2,6-diacetylpyridine dioxime, ferric chloride hydrate, and phenylboronic acid as starting materials the macrocyclic dinuclear iron(ll) complexes 133 can be prepared (Fig. 36). 

A dinuclear iron(ll/Ill) complex bearing a hexadentate phenol ligand displayed moderate activity toward aziridination of alkenes with PhlNTs a large excess of alkene (2,000 equiv. vs PhlNTs) was required for good product yields (Scheme 22) [76]. It is noteworthy that complex 4 is active in the aziridination of aliphatic alkenes, affording higher product yields than copper (11) catalysts with tetradentate macrocyclic ligands [77]. 

Complex (51b) was prepared according to Equation (11). The dangling formyl groups can be used for further derivatization (e.g., (517) shown in Figure 16), and (516) serves as a valuable starting material for the synthesis of macrocyclic dinuclear species (compare Section 6.3.4.12).1367... 

Macrocyclic Schiff base compartmental ligands (750) (Robson-type ligands) derived from the [2 + 2] condensation of a 2,6-diformyl- or 2,6-diketo-substituted phenol and a diamine are very prominent in dinuclear Ni coordination chemistry.1901-1903 Particular interest lies in magnetic exchange interactions between the adjacent metal ions as well as in bioinorganic chemistry, where such dinuclear complexes have been proposed as synthetic analogues for bimetallosites. 

Similarly, by Schiff-base condensation reactions have been used to generate free cryptands from triamines and dicarbonyls in [2+3] condensation mode. These ligands react with silver(I) compounds to give dinuclear or trinuclear macrocyclic compounds where Ag Ag interactions may be present. Thus, with a small azacryptand a dinuclear complex with a short Ag- Ag distance (55) is found.498 With bigger azacryptand ligands also dinuclear complexes as (56) are achieved but without silver-silver interaction. 65,499-501 A heterobinuclear Ag1—Cu1 cryptate has also been... 

An 18-membered N3O3 macrocycle could not be synthesized with transition metal templates but the N402 analog (85) was successfully synthesized with a zinc template. This gave dinuclear /r-hydroxy bridged zinc complexes including a rare example of a single unsupported... 

The zinc complex of a 14-membered CA-N2S2 dibenzo macrocycle with two pendent pyridyl-methyl groups was studied (L = 8,ll-bis(2-pyridylmethyl)5,6,7,8,9,10,16,17-octahydro-diben-zo[e,m][l,4]dithia[8,ll]diazacyclotetradecine). In solution, [ZnL]2+ takes up atmospheric carbon dioxide and transforms to the dinuclear complex [(//-C03)(ZnL)2](C104)2. The structures of both complexes have been elucidated. The zinc atoms, which are situated outside the macrocyclic ring, are unsymmetrically bridged by the //-carbonato group.739... 

Macrocyclic ligands 1,4,7-triazacyclonona-iV-acetate 221 and iV-(2-hydroxybenzyl)-l,4,7-cyclononane 225 have been prepared from l,4,7-triazacyclio[5.2.1.04 10]decane 40 and were subsequently used for the synthesis of a series of mono- and dinuclear complexes of vanadium(rv) and (v) (Scheme 35) <1995ICA(240)217>. 

---