T
he metat
hesis reactions of (t
hf)
4Ca(P
h)I wit
h t
he corresponding potassium compounds
KR yield t
he
heteroleptic arylcalcium derivatives (t
hf)
3Ca(P
h)[N(SiMe
3)
2] (
1) and (t
hf)
4Ca(P
h)PP
h2 (
2), due to t
heinsolubility of KI in common organic solvents. However, t
he reaction of KCp and KOC
6H
2-2,6-
tBu-4-Me wit
h (t
hf)
4Ca(P
h)I give t
he
homoleptic compounds (t
hf)
2CaCp
2 (
3) and (dme)CaCp
2 (
4) (dependingon t
he solvent) as well as (t
hf)
3Ca(OC
6H
2-2,6-
tBu-4-Me)
2 (
5). Dip
henylcalcium decomposed under t
hesereaction conditions. T
he reaction of K[(Me
3SiN)
2CP
h] wit
h (t
hf)
4Ca(P
h)I yields [{(t
hf)
3Ca}
2{4,4-P
h2-2,6-(C
6H
4)
2C
3N
3}(
![](/images/entities/mgr.gif)
-I)] (
6). T
his di
hydrotriazine derivative forms due to a slow liberation of benzonitrilefrom t
he starting
N,
N'-bis(trimet
hylsilyl)benzamidinate. A solvent c
hange in order to s
hift t
he Sc
hlenkequilibrium (2 P
hCaI=CaP
h2 + CaI
2) toward t
he
homoleptic dip
henylcalcium leads immediately to et
hercleavage reactions and t
he formation of [{(Et
2O)CaP
h2}
4·(Et
2O)CaO] (
7), w
hic
h precipitates from diet
hylet
her. T
his cage compound contains an oxygen-centered Ca
5 square pyramid wit
h t
he p
henyl groupsbridging all Ca···Ca edges.