Crystal and molecular structure of the 4:3 complex of 18-crown-6 ether with neodymium nitrate

Synthesis and crystal structures of PrIII and NdIII complexes with the macrocyclic cavitand cucurbit[6]uril

“…20- 22 The Nd(2)-O dis tances in [Nd(NO 3 ) 6 ] 3-(see Table 1) agree well with the data published in the literature. 21- 23 The crystal packing of the structure of 2 is presented in Fig. 5 6 This structure can also be described as a pseudohexagonal packing of infinite polymeric chains consisting of CB [6] molecules, which are linked to the calcium cations through the carbonyl groups.…”

Structural studies of lanthanide nitrate–N,N′-dimethyl-N,N′-diphenylpyridine-2,6-dicarboxyamide complexes

“…The 12-coordinated complex contained both tridentate and bidentate ligands and is very rare although several types of 12-coordinated complexes for La(III), Ce(III), Pr(III), Nd(III) and Sm(III) have been reported so far [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36].…”

Structural and Spectroscopic Investigations of the 1:1 Complex between Europium Nitrate and a Tetraoxadiaza Macrocycle

“…The presence of the two amine groups has a stabilizing influence, and lanthanide complexes with this ligdnd are approximately three orders of magnitude more stable than corresponding complexes with the cyclic hexaether 18-crown-6 [2] (1,4,7,10,13,16-hexaoxacyclooctadecane). No structural data are available for lanthanide coronates with the ligand (2,2), and it is not known if these compounds are simple neutral 1 : 1 complexes, or if they contain cationic species of the type [LnX,L]+ similar to those observed in complexes of 18-crown-6 ether with lanthanide nitrates [6] [7] or chlorides [8].As part of our work on macrocyclic complexes, we report the crystal structure determination of the 1 :I complex between europium(II1) nitrate and the ligand (2,2), along with a discussion of the nitrate vibrational modes.The use of trivalent lanthanide ions to probe the metal-ion binding sites of ionophores is well-established [2], particularly in conjunction with laser-luminescence techniques. To set a basis for further studies on dinuclear cryptands [ 5 ] , we also report the low-temperature emission spectrum of the complex with ligand (2,2).…”