Synthesis and structure of a 12-crown-4 sandwich complex of manganese(II), bis(1,4,7,10-tetraoxacyclododecane)manganese(II) tribromide

Identification of the Structural Boundary between [Ln(18-crown-6)(NO3)3] and [Ln(NO3)3(H2O)3] · 18-crown-6 Motifs in the Lanthanide Series

“…In this way, the entire crystal lattice is ªgluedº together via these water/ crown interactions (Figure 1). A similar orientation has been observed with transition metal nitrates containing 12-crown-4 and 18-crown-6 as ligands and cocrystallised agents [4,5,27,28]. From our investigations, it has been found that the analogous europium complex is isostructural, adopting an identical non-threaded orientation with the coordinated water molecules participating in hydrogen bonding with the heteroatoms of the crown.…”

“…In these ªhost-guestº type compounds, direct incorporation of the alkali metal ion within the cavity occurs. The stability of these complexes, once thought to be solely dependent on the ionic radii/ macrocyclic cavity ratio has more recently been shown to depend on a variety of factors, including solvent, ligand rigidity, cation charge and presence of hydrogen bond donor atoms [3,4]. The more diverse transition metal series have also received significant attention [4±7].…”

NBO–NEDA, NPA, and QTAIM studies on the interactions between aza-, diaza-, and triaza-12-crown-4 (An-12-crown-4, n=1, 2, 3) and Li+, Na+, and K+ ions

“…In his study, Pedersen showed that these compounds tend to form stable complexes with alkali and alkaline earth metal ions. One decade later, in further studies, scientists showed that these compounds can also interact strongly with transition metal ions [2][3][4]. Crown etherÁ Á Áion interaction is a kind of host-guest chemistry, in which crown ether is host and ion plays as a role of guest.…”

The First Sandwich Complex with an Octa(thioether) Coordination Sphere: Bis(maleonitrile‐tetrathia‐12‐crown‐4)silver(I)

“…[1] In these complexes, for example [Na(12O 4 ) 2 ]Cl·5H 2 O, [2] [Mn-(12O 4 ) 2 ][Br 3 ] 2 , [3] [Li(12O 4 ) 2 ][PPh 2 ], [4] [Ag(12O 4 ) 2 ][AsF 6 ], [5] [Fe(12O 4 ) 2 ][PF 6 ] 2 , [6] [In(12O 4 )][SbCl 6 ]·3CH 3 CN, [7] and [Zn(12O 4 2 , [8] the metal ion is coordinated to eight oxygen atoms to form an octa(oxygen) coordination sphere which is not accessible with acyclic ligands. In early studies of crown ether chemistry the structures of bis(12-crown-4)-metal ion sandwich complexes and the properties of the coordinated metal ions were of interest.…”

“…[20] Previously, we have found that 1,4-dithiacrown ethers are stabilized in endodentate conformations by incorporating the rigid maleonitrile unit between the two sulfur atoms. The resulting maleonitrile-dithiacrown ethers [21] are preorganized S 2 O n coronands (n = [2][3][4][5] …”