T
he reaction of thallium ethoxide with [H(OEt
2)
2][H
2N{B(C
6F
5)
3}
2] in diethyl et
her afforded [Tl(OEt
2)
3][H
2N{B(C
6F
5)
3}
2] (
2a), [Tl(OEt
2)
4][H
2N{B(C
6F
5)
3}
2] (
2b), or [Tl(OEt
2)
2][H
2N{B(C
6F
5)
3}
2]·CH
2Cl
2 (
2c),depending on t
he reaction conditions. T
he dication in t
he hydrolysis product [Tl
4(
3-OH)
2][H
2N{B(C
6F
5)
3}
2]
2·4CH
2Cl
2 consists of two bridging and two terminal Tl
+ ions bound to triply bridging hydroxides. HeatingEt
2O complexes in to
luene afforded [Tl(
6-to
luene)
n][H
2N{B(C
6F
5)
3}
2] (
4,
n = 2, 3), while C
6Me
6 additiongave t
he first thallium-C
6Me
6 adduct, [Tl(
6-C
6Me
6)
2][H
2N{B(C
6F
5)
3}
2]·1.5CH
2Cl
2 (
5a), a bent sandwichcomplex with very short Tl···centroid distances. T
hese arene complexes show no close contacts betweencations and anions. Displacement of to
luene ligands by ferrocene gave [Tl
2(FeCp
2)
3][H
2N{B(C
6F
5)
3}
2]
2·5CH
2Cl
2 (
6) which contains t
he multidecker cations [Tl(FeCp
2)]
+ and [Tl(FeCp
2)
2]
+ in a 1:1 ratio. By contrast,decamethylferrocene leads to electron transfer; t
he isolable thallium-ferrocene complexes may t
hereforebe viewed as precursor complexes for this redox step. With 18-crown-6 t
he complexes [Tl(18-crown-6)
2][H
2N{B(C
6F
5)
3}
2] (
11a) and [Tl(18-crown-6)][H
2N{B(C
6F
5)
3}
2]·2CH
2Cl
2 (
11b) were isolated. T
he structureof t
he latter shows an eight-coordinate thallium ion, w
here t
he coordination to t
he six oxygen donors inequatorial positions is completed by axial contacts to two F atoms of t
he counter anions. T
he bondingbetween thallium(I) and arenes was explored by density-functional t
heory (DFT) calculations. T
he optimizedgeometry of [Tl(tol)
3]
+ converged to a structure very similar to that obtained experimentally. Calculationson [Tl(C
6Me
6)
2]
+ (
5b) to establish w
het
her a linear or bent geometry is t
he most stable revealed a very flatpotential-energy surface for distortions of t
he Ctr(3)-Tl-Ctr(4) angle. Overall, t
here is very little energeticpreference for one particular geometry over anot
her above about 140
, in good agreement with t
hecrystallographic geometry. T
he calculated Tl-arene interaction energies increase from 73.7 kJ mol
-1 forto
luene to 121.7 kJ mol
-1 for C
6Me
6.