hm the datasheet is not so clear -
you can try to use the i2c_scanner
there is another I2C Scanner out there.
as fare as i know normaly you have to use the begin and end Transmission funcitons.
otherweise the i2c or TWI will not work.
you can also check the return of the Wire.endTransmission()
byte, which indicates the status of the transmission:
1:data too long to fit in transmit buffer
2:received NACK on transmit of address
3:received NACK on transmit of data
for your chip are not much infos available..
pleas report back if you found something out.
sunny greetings stefan