Variation of Heterometallic Structural Motifs Based on [W(CN)₈]³⁻ Anions and Mn^II Ions as a Function of Synthetic Conditions

Abstract

Reactions of [W(CN)(8)](3-/4-) anions with complexes of Mn(2+) ion with tridentate organic ligand 2,4,6-tris(2-pyridyl)-1,3,5-triazine (tptz) lead to a series of heterobimetallic complexes. The crystal structures of these compounds are derived from the same basic structural fragment, namely a W(2)Mn(2) square constructed of alternating cyanide-bridged W and Mn ions. In [Mn(II)(tptz)(OAc)(H(2)O)(2)](2){[Mn(II)(tptz)(MeOH)(1.58)(H(2)O)(0.42)](2)[W(V)(CN)(8)](2)}.5 MeOH.9.85 H(2)O (3), isolated molecular squares are co-crystallized with mononuclear cationic Mn(II) complexes. The structure of {[Mn(II)(tptz)(MeOH)](2)[W(IV)(CN)(8)].2 MeOH}(infinity) (4) is based on an infinite chain of vertex-sharing squares, while {[Mn(II) (2)(tptz)(2)(MeOH)(3)(OAc)][W(V)(CN)(8)].3.5 MeOH0.25 H(2)O}(infinity) (5) and {[Mn(II) (2)(tptz)(2)(MeOH)(3)W(V)(CN)(8)][Mn(II)(tptz)(MeOH)W(V)(CN)(8)].2 H(2).OMeOH}(8) (7) are derived from such an infinite chain by removing one of the W-C[triple bond]N-Mn linkages in each of the squares. The decanuclear cluster [Mn(II) (6)(tptz)(6)(MeOH)(4)(DMF)(2)W(V) (4)(CN)(32)].8.2 H(2)O.2.3 MeOH (6) is a truncated version of structure 4 and consists of three vertex-sharing W(2)Mn(2) squares. The structure of [Mn(II)(tptz)(MeOH)(NO(3))](2)[Mn(II)(tptz)(MeOH) (DMF)](2)[W(V)(CN)(8)](2).6 MeOH (8) consists of a hexanuclear cluster, in which the central W(2)Mn(2) square is extended by two Mn side-arms attached via CN(-) ligands to the W corners of the square. The magnetic behavior of these heterobimetallic complexes (except for 4) is dominated by antiferromagnetic coupling between Mn(II) and W(V) ions mediated by cyanide bridges. Compounds 3, 6, and 8 exhibit high spin ground states of S=4, 13, and 9, respectively, while 5 and 7 exhibit behavior typical of a ferrimagnetic chain with alternating spin centers. Complex 4 contains diamagnetic W(IV) centers but holds promise as a potential photomagnetic solid.

Two bimetallic W(IV)-Mn(II) complexes based on octacyanometallates: structures and magnetic properties

“…19 (2) Å. The W-C-N linkages are fairly linear, with the angles ranging from 174(2)° to 179(2)° and are comparable with the range (174.3°-179.7°) found in common octacyanotungstate-manganese bimetallic complexes [12,[18][19][20][21][22][23][24][25][26][27] (a special case of W-C-N = 172.8° was found [20] in a cocrystallized complex with two zigzag chains of (Mn 2 W) ∞ +(MnW) ∞ ). The Mn atoms are hexacoordinate and have a distorted octahedral geometry, consisting of four N atoms from two bidentate dpa ligands and two N atoms from bridging CN groups.…”

“…19(2)-2. 20(1) Å, which are similar to the values reported for 1-D Mn complexes such as [21] {[Mn 3 Ⅱ (bipy) 2 - Symmetry transformations used to generate equivalent atoms: #1 x, −y + 2, z + 1/2; #2 x, −y + 2, z−1/2. (7) Mn (1) Symmetry transformations used to generate equivalent atoms: #1 −x, −y + 2, −z + 2; #2 −x + 1, −y + 2, −z + 2; #3 −x, y + 1/2, −z + 3/2; #4 x − 1, y, z; #5 −x, y − 1/2, −z + 3/2; #6 −x − 1, y − 1/2, −z + 3/2; #7 −x − 1, y + 1/2, −z + 3/2; #8 x + 1, y, z.…”

“…Ⅱ ions which have been studied structurally and magnetically [18][19][20][21][22][23][24][25][26][27] , some of which exhibit very interesting structures and/or magnetic properties. For example: (i) The first octacyanometallate-based cluster {Mn 9 [W(CN) 8 ] 6 } shows a full-capped cubane structure and large spin value of S = 39 / 2 in its ground state [18] , while pentanuclear [Mn Ⅱ (bpy) 2 ][Mn Ⅱ (bpy) 2 (H 2 O)] 2 [W V (CN) 8 ] 2 ·7H 2 O (bipy = 2,2'-bipyridine) exhibits [19] long-range magnetic ordering below T C = 0.66 K; (ii) a neutral one-dimensional 3,2-chainlike bimetallic complex reveals the coexistence of long-range ferromagnetic ordering and glassy behavior [21] ; (iii) pentadecanuclear high spin clusters as building blocks can form 3-D open networks [23] ; (iv) a relatively high magnetic transition temperature has been observed in some 3-D Mn-W V (CN) 8 networks [24,25,27] .…”

A high-spin cyanide-bridged Mo6Mn9 cluster: crystal structure and magnetism

“…Following the pioneering work of Kahn's group [13][14][15], these flexible species may be used as versatile synthons to construct a variety of architectures or networks with novel topological structures and interesting magnetic properties. For example, M V -Mn II [16][17][18][19][20][21][22][23][24][25][26], M VMn III , [27,28], and M V -Cu II [29][30][31][32][33][34][35][36][37][38][39][40], bimetallic assemblies with a variety of extended structures, have been obtained; a few polynuclear clusters with M 6 V Mn 9 II type (M = Mo and W) have been reported as well [41][42][43][44][45][46] …”

Three types of heterometallic structural motifs based on [Mo(CN)8]3−/4− anion and MnII cation as building blocks

“…Following the pioneering work of Kahn's group [13][14][15], these flexible species may be used as versatile synthons to construct a variety of architectures or networks with novel topological structures and interesting magnetic properties. For example, M V -Mn II [16][17][18][19][20][21][22][23][24], M V -Cu II [25][26][27][28][29][30][31][32][33][34][35], and M 6 V Mn 9 II (a few polynuclear clusters) [36][37][38][39] (M = Mo and W) bimetallic assemblies with a variety of extended structure have been obtained. In order to provide more examples of Mo V or Mo IV ion with CN --bridged system, in this paper, [Mo V (CN) 8 ] 3-and Mn II ions are utilized as building blocks for designing and synthesis of Mo V /Mn II magnetic compounds.…”