Crown ether complexes of lead(II) nitrate. Crystal structures of the 12-crown-4, 15-crown-5, benzo-15-crown-5 and 18-crown-6 complexes
Crown ether complexes of lead(II) nitrate. Crystal structures of the 12-crown-4, 15-crown-5, benzo-15-crown-5 and 18-crown-6 complexes
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硝酸铅(II)的冠醚配合物。
DOI：
10.1016/s0020-1693(00)80755-0
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
A. Bond
中科院分区：
文献类型：
--
作者：
R. Rogers;A. Bond
在CH3CN和CH3OH混合溶剂中，普通冠醚与Pb(NO3)2直接反应生成了几种晶体配合物，并对其结构进行了表征。晶体结构为：[Pb(NO3)(12-冠-4)2][Pb(NO3)3(12-冠-4)](1)，[PbL2][PbN3)3 L]2(L=15-冠-5(2)或苯并-15-冠-5(3))，[PbNO3)2(18-冠-6)](4)。正如预期的那样，18-冠-6的空腔大小与Pb2+的离子半径相匹配，铅离子正好位于冠醚的中心。对于所有四种结构，铅O的分离范围为2.645(8)-3.06(1)？(冠醚)和2.53(1)-2.809(8)？(硝酸盐)。键距的变化与配位数、几何构型和离子电荷的不同有关，但没有区分孤对效应。单斜晶系P21/c，在22℃时a=8.237(5)，b=28.464(9)，c=16.331(8)，β=93.77(7)°，D calc=2.07g cm−3，Z=4个公式单元，R=0.038；2：正交晶系，PCcn，在22℃时，a=37.462(5)，b=9.586(2)，c=17.378(4)，D calc=2.00g cm−3，Z=4(严重无序使结构无法完全确定)；α=112.11(3)，β=98.01(2)，γ=104.32(2)°，D calc=1.92g cm−3(Z=2)，R=0.052(8505个反射)；4：单斜晶系，P21/c，在22℃时，a=8.171(8)，b=15.499(9)，c=7.856(8)，β=105.08(7)°，D calc=2.06g cm−3，Z=2，R=0.034(1018反射)。
The straightforward reaction of common crown ethers with Pb (NO 3) 2 in CH 3 CN and CH 3 OH mixtures has produced several crystalline complexes which have been structurally characterized. Crystallographic analysis reveals the following formulations:[Pb (NO 3)(12-crown-4) 2][Pb (NO 3) 3 (12-crown-4)](1),[PbL 2][Pb (NO 3) 3 L] 2 (L= 15-crown-5 (2) or benzo-15-crown-5 (3)), and [Pb (NO 3) 2 (18-crown-6)](4). As anticipated the cavity size of 18-crown-6 matches the ionic radius of Pb 2+ and the lead ion resides exactly in the center of the crown ether. For all four structures, the Pb O separations range from 2.645 (8)–3.06 (1) Å (crown ether) and 2.53 (1)–2.809 (8) Å (nitrate). Variations in bond distances are noted relating to differences in coordination number, geometry and ionic charge, however, a lone pair effect is not distinguished. The crystallographic parameters are as follows: 1: monoclinic, P2 1/c with (at 22° C) a= 8.237 (5), b= 28.464 (9), c= 16.331 (8) Å, β= 93.77 (7)°, D calc= 2.07 g cm− 3 for Z= 4 formula units, and R= 0.038 utilizing 4596 independent observed (F o⩾ 5σ (F o)) reflections; 2: orthorhombic, Pccn with (at 22° C) a= 37.462 (5), b= 9.586 (2), c= 17.378 (4) Å, and D calc= 2.00 g cm− 3 for Z= 4 (severe disorder precluded a complete structure determination); 3: triclinic, P 1 with (at 22° C) a= 10.392 (2), b= 18.799 (6), c= 21.069 (8) Å, α= 112.11 (3), β= 98.01 (2), γ= 104.32 (2)°, D calc= 1.92 g cm− 3 for Z= 2, and R= 0.052 (8505 reflections); 4: monoclinic, P2 1/c with (at 22° C) a= 8.171 (8), b= 15.499 (9), c= 7.856 (8) Å, β= 105.08 (7)°, D calc= 2.06 g cm− 3 for Z= 2 and R= 0.034 (1018 reflections).