Complexes of the ligand 1,5,8,12-tetraazadodecane (3,2,3-tet) with manganese(III) and with a valence-trapped manganese(III)/manganese(IV) hexanuclear array. Crystal and molecular structures of [trans-Mn(3-IOBz)2(3,2,3-tet)](ClO4) and [Mn6(3,2,3-tet)4O6(OAc)3]I5.cntdot.2H2O.cntdot.4C4H8O

Structure and Magnetic Properties of a Mixed-Valence Heptanuclear Manganese Cluster

“…oxygen atoms have been often observed in the core of alkoxoiron(III) clusters, with the metal ions arranged in a single planar array. ,9a, More than two layers of oxygen atoms following the abcabc... pattern (cubic closest packing) have been observed in a few instances. 9b,c In manganese chemistry, this structural motif is apparently less common. Among previously reported examples are mixed-valence [Mn 7 (OH) 3 Cl 3 (hmp) 9 ] 2+ ( 8 ) , and [Mn 10 O 14 (tren) 6 ] 8+ ( 9 ), 5c, which contain double layers of donor atoms (O, N, Cl in 8 ; O, N in 9 ). Due to the presence of oxygen donors only in the coordination sphere of the metal ions, complexes 1 and 2 represent the most accurate models so far obtained for the infinite lattices of layered manganese oxide minerals.…”

“…Only three of such compounds have been reported so far: [Mn 4 O 2 (tphpn) 2 (H 2 O) 2 (CF 3 SO 3 ) 2 ] 3+ , in which a Mn III Mn IV pair is flanked by two Mn II ions, ,29a [Mn 12 O 12 (O 2 CEt) 16 (H 2 O) 4 ] − , whose core has a Mn IV 4 Mn III 7 Mn II stoichiometry,4f and [Mn 13 O 8 (OEt) 6 (O 2 CPh) 2 ], a molecule with a “supercubane” structure 29b. In contrast, high-nuclearity mixed-valence Mn II,III complexes are quite common. 4i-l,5a,b,6a,b,, Consequently, the first stoichiometry proposed seems the most probable. Furthermore, it is consistent with the metrical parameters of the core, as discussed hereafter.…”

“…From a synthetic point of view, chemists have learned to exploit hydrolytic reactions which naturally lead to insoluble metal oxides and oxohydroxides as final products. By proper use of suitable organic ligands, mainly carboxylates, polyamines, and polyols, the “growth” of the metal cores can be controlled in such a way to obtain finite-size clusters. Alkoxide ligands represent an alternative, powerful tool for assembling metal clusters, − as demonstrated by recent work on alkoxoiron(III) complexes, ,9a-c, whose metal/ oxygen cores often exhibit closest-packing layered structures which are typical of bulk metal oxides.…”

Structural motifs and topological representation of Mn coordination clusters

“…In 1990, Weatherburn and co-workers reported the hexanuclear manganese complexes [Mn III 6 (3,2,3-tet) 4 (O 2 CR) 3 O 6 ]-I 5 Á2H 2 OÁ4C 4 H 8 O ( 14) (where R = Me, Ph, 3,2,3-tet = 1,5,8,12-tetraazadodecane). 113 The compounds crystallise in the monoclinic space group C2/c. No magnetic studies were presented.…”

“…Mn(1) and Mn( 5 The Eu analogue of this compound was also reported. 19 By comparing the cartoon representation of the pentadecanuclear metallic cores of Mn 13 Ca 2 (113), Mn 14 Sr (114) and Mn 11 Dy 4 (123), it is obvious that those cores are closely related.…”