Tetranuclear manganese carboxylate complexes with a trigonal pyramidal metal topology via controlled potential electrolysis.
Tetranuclear manganese carboxylate complexes with a trigonal pyramidal metal topology via controlled potential electrolysis.
复制标题
DOI：
10.1021/ic991068m
复制
发表时间：
2000-03
影响因子：
4.6
通讯作者：
S. Wang;M. Wemple;J. Yoo;K. Folting;J. Huffman;K. Hagen;D. Hendrickson;G. Christou
中科院分区：
文献类型：
--
作者：
S. Wang;M. Wemple;J. Yoo;K. Folting;J. Huffman;K. Hagen;D. Hendrickson;G. Christou
描述了控制电位电解（CPE）程序，其提供了从含有[Mn 4（mu 3-O）2]8+核（4 Mn III）的物质开始的具有[Mn 4（mu 3-O）3（mu 3-O2 CR）]6+核（3 Mn III，Mn IV）和三角锥金属拓扑结构的络合物。[Mn4O2（O2CMe）6（py）2（dbm）2]（6）：三斜晶系，P1，a = 10.868（3）A，B = 13.864（3）A，c = 10.625（3）A，α = 108.62（1）度，β = 118.98（1）度，γ = 89.34（2）度，V = 1307 A3，Z = 1，T = -131 ℃，R（Rw）= 3.24（3.70）%。[Mn 4 O2（O2 CPh）6（py）（dbm）2]（8）：单斜晶系，P2（1）/c，a = 14.743（6）A，B = 15.536（8）A，c = 30.006（13）A，β = 102.79（1）度，V = 6702 A3，Z = 4，T = -155 ℃，R（Rw）= 4.32（4.44）%。6和8都含有[Mn 4 O2]8+核心; 8只有一个py基团，第四个MnIII位点是五配位的。（NBun 4）[Mn 4 O 2（O 2 CPh）7（dbm）2]（10）可从两个相关程序获得。在MeCN中，在0.65 V下相对于二茂铁的CPE为10，导致[Mn 4 O3（O2 CPh）4（dbm）3]沉淀（11）;类似地，在MeCN/CH 2Cl 2（3：1 v/v）中，在0.84 V下CPE为6，得到[Mn 4 O3（O2 CMe）4（dbm）3]（12）。复合体11：单斜晶系，P2（1）/n，a = 15.161（3）A，B = 21.577（4）A，c = 22.683（5）A，β = 108.04（3）度，V = 7056 A3，Z = 4，T = -100 ℃，R（wR 2）= 8.63（21.80）%。复合体12：单斜晶系，P2（1）/n，a = 13.549（2）A，B = 22.338（4）A，c = 16.618（2）A，β = 103.74（1）度，V = 4885 A3，Z = 4，T = -171 ° C，R（Rw）= 4.63（4.45）%。11和12都含有[Mn 4（mu 3-O）3（mu-O2 CR）]核，其具有Mn 4三角锥（顶点处的MnIV）和桥接MnIII 3基底的RCO 2。然而，在11中，羧酸盐是eta 2，mu 3，其中一个O原子末端连接到一个MnIII，另一个O原子桥接其他两个MnIII离子，而在12中，羧酸盐是eta 1，mu 3，单个O原子桥接三个MnIII离子。变温，固态磁化率的研究11和12表明，对于这两个复合物，有反铁磁交换相互作用之间的MnIII/MnIV对，和铁磁相互作用之间的MnIII/MnIII对。在这两种情况下，复合物的合成基态均为S = 9/2，分别通过2.00-30.0 K和0.50-50 kG温度和场范围内的磁化强度与场研究证实。
Controlled potential electrolysis (CPE) procedures are described that provide access to complexes with a [Mn4(mu 3-O)3(mu 3-O2CR)]6+ core (3MnIII,MnIV) and a trigonal pyramidal metal topology, starting from species containing the [Mn4(mu 3-O)2]8+ core (4MnIII). [Mn4O2(O2CMe)6(py)2(dbm)2] (6): triclinic, P1, a = 10.868(3) A, b = 13.864(3) A, c = 10.625(3) A, alpha = 108.62(1) degrees, beta = 118.98(1) degrees, gamma = 89.34(2) degrees, V = 1307 A3, Z = 1, T = -131 degrees C, R (Rw) = 3.24 (3.70)%. [Mn4O2(O2CPh)6(py)(dbm)2] (8): monoclinic, P2(1)/c, a = 14.743(6) A, b = 15.536(8) A, c = 30.006(13) A, beta = 102.79(1) degrees, V = 6702 A3, Z = 4, T = -155 degrees C, R (Rw) = 4.32 (4.44)%. Both 6 and 8 contain a [Mn4O2]8+ core; 8 only has one py group, the fourth MnIII site being five-coordinate. (NBun4)[Mn4O2(O2CPh)7(dbm)2] (10) is available from two related procedures. CPE of 10 at 0.65 V vs ferocene in MeCN leads to precipitation of [Mn4O3(O2CPh)4(dbm)3] (11); similarly, CPE of 6 at 0.84 V in MeCN/CH2Cl2 (3:1 v/v) gives [Mn4O3(O2CMe)4(dbm)3] (12). Complex 11: monoclinic, P2(1)/n, a = 15.161(3) A, b = 21.577(4) A, c = 22.683(5) A, beta = 108.04(3) degrees, V = 7056 A3, Z = 4, T = -100 degrees C, R (wR2) = 8.63 (21.80)%. Complex 12: monoclinic, P2(1)/n, a = 13.549(2) A, b = 22.338(4) A, c = 16.618(2) A, beta = 103.74(1) degrees, V = 4885 A3, Z = 4, T = -171 degrees C, R (Rw) = 4.63 (4.45)%. Both 11 and 12 contain a [Mn4(mu 3-O)3(mu-O2CR)] core with a Mn4 trigonal pyramid (MnIV at the apex) and the RCO2- bridging the MnIII3 base. However, in 11, the carboxylate is eta 2,mu 3 with one O atom terminal to one MnIII and the other O atom bridging the other two MnIII ions, whereas in 12 the carboxylate is eta 1,mu 3, a single O atom bridging three MnIII ions. Variable-temperature, solid-state magnetic susceptibility studies on 11 and 12 show that, for both complexes, there are antiferromagnetic exchange interactions between MnIII/MnIV pairs, and ferromagnetic interactions between MnIII/MnIII pairs. In both cases, the resultant ground states of the complex is S = 9/2, confirmed by magnetization vs field studies in the 2.00-30.0 K and 0.50-50 kG temperature and field ranges, respectively.