Solvent-free mesityllithium: solid-state structure and its reactivity towards white phosphorus

Abstract

The donor-free mesityllithium was prepared from the reaction of MesBr with n-BuLi in diethyl ether at -78 degrees C. The solid-state structure of unsupported mesityllithium consists of C(2)Li(2)-rings composed of two LiMes units, which interact with adjacent dimers [LiMes](2), forming a polymeric infinite chain along the crystallographic c-axis (monoclinic space group, P2(1)/n). The structure of donor-free mesityllithium reveals short contacts between the C atoms of the mesityl rings and the lithium atoms of neighbouring [LiMes](2) units. The structure determination of LiMes was performed by X-ray powder diffraction. In addition we have investigated the reaction of LiMes with Me(3)SnCl and P(4) for our understanding of the reactivity of donor-free mesityllithium. The heterogeneous reaction of donor-free mesityllithium with Me(3)SnCl produces conveniently the stannylated mesitylene Me(3)SnMes (triclinic, space group P1). White phosphorus reacts with three equivalents of unsupported mesityllithium in benzene to give Li(3)P(4)Mes(3). In this context it should be noted that a tetraphosphide with an identical LiP-core as in Li(3)P(4)Mes(3) had been formed in the 1:3 reaction of P(4) with the silanide Li[SitBu(3)]. The tetraphosphide Li(3)P(4)Mes(3) was analyzed using X-ray crystallography (monoclinic, space group C2/c).

A Quest for Ligand‐Unsupported Li+–π Interactions in Mono‐, Di‐, and Tritopic Lithium Arylborates

“…[14] Category (3) consists of aryllithium compounds that show Li + -π coordination in addition to Li-C σ bonds. [15] Examples are Lewis base-free phenyllithium ([LiPh] n ), [16] mesityllithium ([LiMes] n ), [17] and 2,4,6-triisopropylphenyllithium ([LiTrip] 4 ); [18] [21] [Li(C 6 H 6 )][Sn{SiMe(tBu) 2 } 3 ], [22] and [Li(C 6 H 6 )][B(C 6 F 5 ) 4 ]. [23] Our own interest in cation-π interactions was sparked by the serendipitous finding that ferrocene reacts with GaCl 3 to give [(C 5 H 5 ) 2 Fe][GaCl 4 ] together with the crystalline Ga I multiple-decker sandwich complex I (Figure 1).…”

Low‐Valent Group 14 NHC‐Stabilized Phosphinidenide ate Complexes and NHC‐Stabilized K/P‐Clusters

“…Only some larger derivatives, mostly containing lithium,a re known in the literature. [38,40,[46][47][48][49][50][51][52][53][54][55][56][57] In contrast to compound 5,t he coordination number of the phosphorus atom in 6 increases to five. The potassium atoms coordinated by two phosphorus atoms (K1 and K1')h aveac oordination number of six (2 P, 2 O, 2 CH 3 agostici nteraction with the methyl groups of the tBu substituents), whereas the potassium atoms solely coordinated by one phosphorusa tom show one agostici nteraction to am ethyl group (K2, K2',K 3, and K3').…”

Electrocyclic Reactions of Siloles: A Combined Experimental and Theoretical Study

“…Reaction of 1 with one equivalent of Li t Bu, Na[Si t Bu 3 ],21, 22 and Na[SiPh t Bu 2 ]21, 23 exclusively led to the corresponding monosubstituted derivatives shown in Scheme . The use of less bulky nucleophiles, such as LiMe, LiPh, or LiMes (Mes=mesityl),24 in excess resulted in nearly quantitative yields of the related literature‐known, disubstituted derivatives 3 .…”