Catharina.Catherina etymology - Katharos or Aikaterine - Slav

From: João S. Lopes Filho
Message: 11409
Date: 2001-11-22

What´s the the etymology of name CATHERINA? Usual sources mention derivation from Greek Aikaterine (or Hekaterine), infl. by katharos "pure".
 
Russian form is YEKATERINA. Does it mean that Byzantine has AI-KATERINA , with no TH? For KATHERINA we d expect KAFERINA. Is there such name?
 
Some languages change CATHARINA to *CATHALINA (Spanish Catalina, Hungarian Katlin, English Cathleen).
 
Portuguese has CATARINA (variation CATERINA), which is erudict, because expected would be *CADRINHA.
 
Joao SL