Role of o-Methylene-Bridged Bis(aniline) as a Spectroscopic Probe for the Metal Coordination Environment
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- 作者：William Lesueur ; Andrew J. Rogers ; Carlo Floriani ; Angiola Chiesi-Villa and ; and Corrado Rizzoli
- 刊名：Inorganic Chemistry
- 出版年：1998
- 出版时间：January 12, 1998
- 年：1998
- 卷：37
- 期：1
- 页码：44 - 49
- 全文大小：231K
- 年卷期：v.37,no.1(January 12, 1998)
- ISSN：1520-510X
文摘
Reaction of the bidentate ligand2,2'-methylenebis(5-(dimethylamino)aniline) (2, L)with PdCl2 and K2PtCl4andthe bidentate ligand 2,2'-methylenebis(5-(acetylamino)aniline(5, L') with K2PtCl4 in polarsolvents gave thecomplexes [PdCl2(L)] (6),[PtCl2(L)] (8), and[(L')PtCl2] (7), respectively.Treatment of 2 withK2PtCl4 in thepresence of DMSO resulted in the solvolysis of a chloride ion to give[(L)Pt(Cl)(DMSO)]Cl (9). Theresultingeight-membered metallocyclic rings have rigid elongated chairconformations forcing one of the two bridgingmethylene hydrogens (Hendo) in close proximity to the metalcentre. An 1H NMR study revealed that theyarenow diastereomeric (Hendo, Hexo); the higherfield signal position does not vary irrespective of the ligand ormetal,whereas the proton corresponding to the lower field signal isapparently more sensitive to the metal coordinationenvironment. The ability of this spectroscopic probe to predictthe bonding mode of the metal was also studiedby reacting 2 withK[PtCl3(C2H4)]·H2Oto give[Pt2(
-L)Cl4(C2H4)2](10), which occurred irrespective of theL/Pt ratio. The corresponding methylene hydrogens were notdiastereomeric, showing only one singlet in the1HNMR spectrum. Crystal structures of 6 and 9have been determined: 6 is triclinic, space groupP
, a = 10.179(2)Å, b = 12.136(2) Å, c = 9.686(2)Å, 
= 97.79(1)
, 
= 95.98(2), 
=78.02(1), V = 1156.1(4), Z = 2,andR = 0.034; 9 is triclinic, space groupP, a = 12.348(1) Å, b= 12.407(1) Å, c = 10.159(1) Å, =103.02(1), = 104.87(2), = 117.09(1), V =1313.0(3), Z = 2, and R =0.035.
-L)Cl4(C2H4)2](10), which occurred irrespective of theL/Pt ratio. The corresponding methylene hydrogens were notdiastereomeric, showing only one singlet in the1HNMR spectrum. Crystal structures of 6 and 9have been determined: 6 is triclinic, space groupP, a = 10.179(2)Å, b = 12.136(2) Å, c = 9.686(2)Å, = 97.79(1), = 95.98(2), =78.02(1), V = 1156.1(4), Z = 2,andR = 0.034; 9 is triclinic, space groupP, a = 12.348(1) Å, b= 12.407(1) Å, c = 10.159(1) Å, =103.02(1), = 104.87(2), = 117.09(1), V =1313.0(3), Z = 2, and R =0.035.