BINUCLEAR, TRINUCLEAR, AND TETRANUCLEAR METALLOMACROCYCLES CONSTRUCTED BY METAL-DIRECTED REACTIONS INVOLVING RESORCINOL OR HYDROQUINONE OR BY ADDITION OF OCTAHEDRAL METAL CENTERS TO TETRAHEXYLCALIX[4]RESORCINARENE - X-RAY CRYSTAL-STRUCTURE OF N,SYN-[MO(HB(3,5-ME2C3HN2)(3))(NO)(1,4-O2C6H4)](3)
Fs. Mcquillan et al., BINUCLEAR, TRINUCLEAR, AND TETRANUCLEAR METALLOMACROCYCLES CONSTRUCTED BY METAL-DIRECTED REACTIONS INVOLVING RESORCINOL OR HYDROQUINONE OR BY ADDITION OF OCTAHEDRAL METAL CENTERS TO TETRAHEXYLCALIX[4]RESORCINARENE - X-RAY CRYSTAL-STRUCTURE OF N,SYN-[MO(HB(3,5-ME2C3HN2)(3))(NO)(1,4-O2C6H4)](3), Inorganic chemistry, 37(19), 1998, pp. 4959-4970
The reaction between [Mo(NO)(Tp)I-2] [Tp(-) = hydrotris(pyrazol-1-yl)b
orate] and tetrahexylcalix[4]resorcinarene (resH(8)) affords a mixture
of metalated macrocycles from which [{Mo(NO)(Tp)}(2)(resH(4))], [{Mo(
NO)(Tp)}(3)(resH(2))], and [{Mo(NO)(Tp)}(4)(res)] can be isolated. In
the solid state the tetrametalated compound can act as a host for CH2C
l2 which forms a weak hydrogen bond to the oxygen of a coordinated nit
ric oxide: H ... O1 2.47 fi, angle C-H ... O1 161 degrees. Direct reac
tion of [Mo(NO)(Tp)I-2] [Tp*(-) = hydrotris(3,5-dimethylpyrazol-1-yl)
borate] with resorcinol itself offers a route to the related resorcino
l-based tetrametallomacrocycle [Mo(NO)(Tp)(1,3-O2C6H4)](4). This react
ion also produces the cyclic trimer [Mo(NO)(Tp)(1,3-O2C6H4)](3) togeth
er with some cyclic dimer. A similar reaction involving 1,4-dihydroxyb
enzene and [M(NO)(Tp)I-2] (M = Mo, W) also affords cyclic trimers and
cyclic tetramers, but in this case, cyclic dimers are not formed. It
has been possible to separate the single isomers syn,syn-[Mo(NO)(Tp)(
1,4-O2C6H4)](3), anti,syn-[M(NO)(Tp)(1,4-O2C6H4)](3) (M = Mo, W), ant
i,syn[Mo(NO)(Tp)(1,3-O2C6H4)](3), and anti,syn,syn-[Mo(NO)(Tp*)(1,3-O
2C6H4)](4). The crystal structure of syn,syn[Mo(NO)(Tp)(1 ,4-O2C6H4)]
(3) has been determined: C63H78B3Mo3N21O9; monoclinic space group P2(1
)/a; a = 16.269(10), b = 35.31(3), c = 16.056(10) Angstrom; beta = 97.
59(2)degrees; Z = 4. The coordination geometry at the molybdenum atoms
is essentially octahedral. The trimer does not show 3-fold symmetry,
the triangle of molybdenum atoms having two long edges, 8.485(3) and 8
.703(3) Angstrom, and one short edge of 7.886(3) Angstrom. These dista
nces an paralleled by the corresponding distances between the nitrosyl
oxygen atoms, 6.177(12), 6.526(12), and 3.729(12) Angstrom, respectiv
ely. The electrochemical properties of the metallomacrocycles reveal d
iffering patterns of redox potentials depending upon the number and ge
ometric arrangement of metal centers in the macrocyclic structure.