Potassium complexes containing both crown ether and tertiary phosphine oxide ligands

The Trifluoromethyl Anion

“…[3] In most instances,h owever, such intermediates in solution are not free anions and cations per se,b ut rather their synthetic equivalents,s ometimes referred to as "synthons". [5] Furthermore,t he abundant literature data [6] and our own research experience [7,8] show that the potassium atom in [K (18-crown-6)] + is coordinatively unsaturated and therefore readily binds to additional ligands.The electrophilicity of the K + in the crown is sufficient to form bonds to abroad variety of electron pair donors,i ncluding those that are vastly weaker nucleophiles than CF 3 À ,such as BF 4 À (see below). [4] Purely ionic compounds,s uch as tetraalkylammonium salts in solvents of low or moderate polarity,T HF included, form tight ion pairs aggregated in clusters.…”

“…[4] Purely ionic compounds,s uch as tetraalkylammonium salts in solvents of low or moderate polarity,T HF included, form tight ion pairs aggregated in clusters. [5] Furthermore,t he abundant literature data [6] and our own research experience [7,8] show that the potassium atom in [K(18-crown-6)] + is coordinatively unsaturated and therefore readily binds to additional ligands.The electrophilicity of the K + in the crown is sufficient to form bonds to abroad variety of electron pair donors,i ncluding those that are vastly weaker nucleophiles than CF 3 À ,such as BF 4 À (see below). Of particular relevance is the fact that tBuOK and 18-crown-6 form as table neutral complex [K(18-crown-6)(tBuO)] that has been characterized in solution and in the crystal state.…”

Synthesis of crown ether complexes of alkali-metallated organophosphine oxides and insertion reactions with isonitriles

“…The closest related compounds to 1 contain neutral organophosphine oxides as solubilizing additives for potassium salts [17,[19][20][21].…”

“…2). Previously sodium complexes with crown ether or phosphine oxide ligands had (like their potassium analogues) mainly been used as counter ions in transition metal complexes and cluster chemistry [17,[19][20][21]. 2 was prepared according to Fig.…”

Synthesis and Crystal Structure of (18-Crown-6)(nitrato)(triphenylphosphine oxide)potassium

“…The synthesis and structures of similar complexes with the general formula [K(An)(18-crown-6)(Ph 3 PO)] of the hostguest type [1] were described in [2] (An = I, Br, and SCN) and in [3] (An = OCN, SCN, and N 3 ). X-ray diffraction analysis was carried out for the complexes with An = I [2] and An = OCN, SCN, and N 3 [3]. The crystal structures of these four complexes are isomorphic and highly symmetric (space group R 3 m ).…”