Crystal structure of 7,15,23,31-tetramethyl-3,11,19,27-tetraazopentacyclo[ 27.16.1611.27.4.411.27.3.35.9.313.17.321.25.1.15.9.113.17.121.25]triaconta- 1(32),5,7,9(34),13,15,17(35),21,23,25(36),29(33),30-dodecaarene- 33,34,35,36-tetraol, C44H56N4O4

Abstract

C 44 H 56 N 4 O 4 ,monoclinic, C12/c1(no. 15), a =23.216(2) Å, b =14.0445(9) Å, c =13.064(1) Å, b =118.413(9)°, V =3746.5 Å 3 , Z =4,Rgt(F) =0.076, wRref (F 2 ) =0.186, T =293 K. Source of materialThe macrocyclic ligand H 2Lwas prepared as reported earlier [1]. Amethanol solution (30 mL) containing H 2L( 0.44 g, 1mmol) was heated to boiling and then slowly treated with amethanol solution (20 mL) of 4-methyl-2,6-diformyl (0.33 g, 2mmol). After stirring for 1h ,a no range precipitate was obtained. Then a amount of solid NaBH 4 was added to the solution. The solid material gradually went into solution, and ultimately an almost colorless solution was obtained over ap eriod of 0.5 h. This was filtered, and to the filtrate was added slowly 30 mL of water with stirring. The resulting solution was allowed to stand overnight, during which period the product separated out as colorless crystals. The product was collected by filtration and recrystallized from methanol/water (yield 35 %ormore). The product (0.077 g, 0.1 mmol) and Ni(OAc) 2. · . 6H 2 O(0.050 g, 0.2 mmol) were dissolved in DMF (5 mL) and water (5 mL). The mixture sealed in a 15 mL Teflon-lined stainless steel autoclave, and heated at 100°C for 4d ays under autogenous pressure. Afterward, the reaction system was gradually cooled to room temperature at ar ate of 10°C/h. Light green crystals were obtained in a34 . %yield. Experimental detailsAll Ha toms on Ca toms were generated geometrically and refined as riding atoms with d(C-H) =0.93 Å and U iso (H) =1.2 or 1.5 U eq (C). The hydroxy Ha tom were located from difference Fourier map and refined with U iso (H) =1 .5 U eq (O). The huge residual values are caused by the vibration of the terminal C21 and C22 atoms at room temperature. DiscussionRecently, the study of metal complexes with phenol-based macrocyclic compartmental ligands has become important in view of their significance as biomimetric catalysts in the process of oxygenation [2]. Several classes of macrocyclic ligands have been synthesized [3]. In the title crystal structure, the intramolecular hydrogen bonds involving the phenolic oxygens are of particular importance because the macrocyclic cation is stabilized by these bonds. The N···Odistances are in the range 2.738 (5) -3.04 (1) Å,while the O-H···Nangles vary between 135°and 140°,which indicates that the intramolecular hydrogen bonds are quite strong. The C-O and C-Nbond lengthes are in the range of 1.37 to 1.45 Å,respectively. The bond distances and bond angles are all in normal range.