CATION-INDUCED STRUCTURAL ALTERATIONS IN THE ORGANO ALKALI-METAL DERIVATIVES OF TRIPHENYLMETHANE - COMBINED X-RAY AND NMR-STUDY OF THE K-CS SALTS

被引:121
作者
HOFFMANN, D
BAUER, W
SCHLEYER, PV
PIEPER, U
STALKE, D
机构
[1] UNIV ERLANGEN NURNBERG, INST ORGAN CHEM, HENKESTR 42, W-8520 ERLANGEN, GERMANY
[2] UNIV GOTTINGEN, INST INORGAN CHEM, W-3400 GOTTINGEN, GERMANY
关键词
D O I
10.1021/om00028a038
中图分类号
O61 [无机化学];
学科分类号
070301 ; 081704 ;
摘要
The set of alkali metal solid-state structures of Ph3CM.nL [M = K, Rb, Cs; L = (ligands) PMDTA (N,N,N',N'',N''-pentamethyldiethylenetriamine), THF (tetrahydrofuran)] provides instructive comparisons. Ph3CK-THF.PMDTA (1) crystallizes as a monomeric contact ion pair: the K+ cation is symmetrically eta6-coordinated to one of the phenyl rings, but not to the deprotonated central carbon. Both [Ph3CRb-PMDTA], (2) and [Ph3CCs-PMDTA]n (3) form one-dimensional polymers and eschew THF. The Rb cations in 2 bridge the triphenylmethyl moieties by eta6-coordination to separate phenyl rings. This gives rise to a zigzag chain. In 3, each Cs cation also bridges two carbanions, but in a somewhat different fashion. While Cs+ is located rather symmetrically (eta6) above the phenyl ring of one trityl moiety, a ''propeller''-like coordination to a second trityl anion involves contacts with all three phenyl rings as well as with the deprotonated central carbon. The structure of 3 in THF-d8 solution was elucidated by Cs-133, H-1 HOESY spectroscopy, which reveals agostic interactions between cesium and hydrogen. This provides strong evidence that 3 is a contact ion pair in this solvent with the cation located above the central carbon. The recently proposed MNDO K parameters err in predicting Ph3CK.nL (1) to be ''oversolvated''; K-C distances and nonbonded repulsion energies are overestimated.
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页码:1193 / 1200
页数:8
相关论文
共 108 条
[1]  
[Anonymous], PREPARATIVE POLAR OR
[2]   TRITYLPOTASSIUM - A NEW DEHYDROHALOGENATION REAGENT [J].
ANTON, DR ;
CRABTREE, RH .
TETRAHEDRON LETTERS, 1983, 24 (24) :2449-2450
[3]  
Atwood J. L., 1977, RECENT DEV SEP SCI, V3, P195
[4]   DECOMPOSITION OF HIGH-OXYGEN CONTENT ORGANO-ALUMINUM COMPOUNDS - THE FORMATION AND STRUCTURE OF THE [AL7O6ME16]- ANION [J].
ATWOOD, JL ;
HRNCIR, DC ;
PRIESTER, RD ;
ROGERS, RD .
ORGANOMETALLICS, 1983, 2 (08) :985-989
[5]   SYNTHESIS OF M[AL2(CH3)6NO3] (M+=K+,RB+,CS+,NR4+) AND CRYSTAL-STRUCTURES OF K[AL2(CH3)6NO3] AND K[AL(CH3)3NO3].C6H6 [J].
ATWOOD, JL ;
CRISSINGER, KD ;
ROGERS, RD .
JOURNAL OF ORGANOMETALLIC CHEMISTRY, 1978, 155 (01) :1-14
[6]   BEHAVIOR OF K[AL2ME6N3], RB[AL2ME6N3], CS[AL2ME6N3] WITH AROMATIC SOLVENTS AND THE CRYSTAL-STRUCTURES OF CS[AL2ME6N3].2 PARA-XYLENE AND [K.DIBENZO-18-CROWN-6] "[AL2ME6N3].1.5(1-METHYLNAPHTHALENE) [J].
ATWOOD, JL ;
HUNTER, WE ;
ROGERS, RD ;
WEEKS, JA .
JOURNAL OF INCLUSION PHENOMENA, 1985, 3 (02) :113-123
[7]  
ATWOOD JL, 1983, J INCLUSION PHENOM, V1, P199
[8]   ISOLATION AND X-RAY CRYSTAL-STRUCTURES OF THE ORGANO-LITHIUM ETHERATE COMPLEXES, [LI(ET2O)2(CPH3)] AND [(LI(ET2O)(2,4,6-(CHME2)3C6H2))2] [J].
BARTLETT, RA ;
DIAS, HVR ;
POWER, PP .
JOURNAL OF ORGANOMETALLIC CHEMISTRY, 1988, 341 (1-3) :1-9
[9]   STRUCTURE OF A SUPER BASE IN TETRAHYDROFURAN SOLUTION STUDIED BY LI-6, H-1 HOESY, CS-133, H-1 HOESY, AND MNDO - EVIDENCE FOR DISCRETE SPECIES RATHER THAN A MIXED AGGREGATE [J].
BAUER, W ;
LOCHMANN, L .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1992, 114 (19) :7482-7489
[10]   CS-133, H-1 2-DIMENSIONAL HETERONUCLEAR OVERHAUSER EFFECT SPECTROSCOPY (HOESY) - STRUCTURAL-ANALYSIS OF ORGANIC CESIUM COMPOUNDS BY DETECTION OF SHORT CS,H CONTACTS [J].
BAUER, W .
MAGNETIC RESONANCE IN CHEMISTRY, 1991, 29 (05) :494-499