Hi Markus,
    According to Don Lancaster's CMOS Cookbook  the pin 1 voltage ranges
from 3 to 15 volts and the pin 16 voltage is specified as 3 to 15, but more
than the pin 1 voltage. You can probably hook pin one to pin 16 via a small
signal diode like the 1n914 but he also states that this is a very old chip.
You should use the functionally equivalent 4049 for newer designs. It has
supplies on 1 and 8 and does'nt require the strangeness.

Good Luck,

Keith Causey