Elucidation of structural relationships and assignment of proton NMR spectra of transition-metal cyclidene complexes by 2-D NMR techniques

Abstract

The complete *H NMR spectra of five nickel cyclidene macrocyclic complexes are assigned by using DEPT (distortionless enhancement by polarization transfer) and 2-D NMR techniques: *H-13C shift correlation, COSY (correlated shift), and NOESY (nuclear Overhauser enhanced correlated shift). The *H NMR assignments are consistent with the complexes having an overall saddle shape with the two saturated six-membered rings (composed of nickel, two nitrogens, and a trimethylene chain) adopting a chair and a boat configuration similar to those observed in the X-ray crystal structures of these complexes. The *H NMR spectra can distinguish between two possible configurations for the bridging moiety (lid-off and lid-on). The vinyl methyl groups, labeled as O and N, have a chemical shift separation greater than 0.35 ppm for a lid-off configuration and less than 0.15 ppm for a lid-on configuration.

Fine‐Tuning of Properties of Bismacrocyclic Dinuclear Cyclidene Receptors by N‐Methylation

“…Additionally, we failed to find water hydrogen atoms. Scattering factors were taken from Tables 6.1.1.4 and 4.2.4.2 in reference [15].…”

Torandsynthese durch Trimerisierung — neue Rezeptoren für Guanidinium

“…Die hervorragende Praorganisation von Wasserstoffbriickenbindungsstellen in 3 sollte eine molekulare Erkennung von Guanidiniumsalzen bewirken. Im 143.0, 142.1, 137.7, 121.8, 117.5, 30.2, 27.9, 25.8, 23.3, 23.0, 22.6, 22.5, 21.6, 13.8 6, 147.1, 135.8, 134.4, 134.3, 133.6, 123.0, 31.9, 28.9, 28.6, 24.8, 23.4, 14.0 'J= 4,8 Hz,2H;20),3.49 (m,16H;CH,7,9,10,13,14,16,17),3.11 (m,4H; CH,nPr), 1.67 (m. 8H; CH,CH,CH,), 1.09 (t, 'J = 7 Hz,6 H ;CH,). 141.1,140.8,140.5,139.2,138.9,136.2,135.2,126.7,126.1,126.0,31.9,30 "C-NMR(CD,OD): 6 = 156.…”

A facile and efficient synthetic approach to novel lariat macrocyclic diamides and bis macrocyclic diamides

“…A number of such compounds have been observed to act as anti-HIV agents, which exhibiting low cytotoxicity [24]. Many other linked mixed-donor macrocycles are also known and open possibilities in cooperative receptors and switching materials [25][26][27][28][29][30][31]. In connection with these findings and in continuation of our interest in synthesizing macrocyclic di-and tetralactams [32][33][34][35][36][37][38], and bis macrocycles [39][40][41] we report here on the synthesis of novel lariat macrocyclic diamides as well as bis(macrocyclic diamides) with enhanced cation binding properties compared with their corresponding precursors.…”