No, there were no legates.
It is too arrogant and intemperate thus to step beyond all proper bounds and trampling on ancient custom to wish to seize another’s right: to increase one man’s dignity at the expense of so many metropolitans’ primacy, and to carry a new war of confusion into peaceful provinces which were long ago set at rest by the enactments of the holy Nicene Synod: to break through the venerable Fathers’ decrees by alleging the consent of certain bishops, which even the course of so many years has not rendered effective. For it is boasted that this has been winked at for almost 60 years now, and the said bishop thinks that he is assisted thereby; but it is vain for him to look for assistance from that which, even if a man dared to wish for it, yet he could never obtain. (St. Leo the Great, Letter 105, To Pulcheria Augusta)
For your purpose is in no way whatever supported by the written assent of certain bishops given, as you allege, 60 years ago, and never brought to the knowledge of the Apostolic See by your predecessors; and this transaction, which from its outset was doomed to fall through and has now long done so, you now wish to bolster up by means that are too late and useless, viz., by extracting from the brethren an appearance of consent which their modesty from very weariness yielded to their own injury. (St. Leo the Great, Letter 106, To Anatolius of Constantinople)
Lucentius the most reverend bishop and legate of the Apostolic See, said: It is manifest that the decrees of the 318 have been put aside, and that mention only has been made of those of the 150, which are not found to have any place in the synodical canons, and which were made as they acknowledge eighty years ago. If therefore they enjoyed this privilege during these years, what do they seek for now? If they never used it, why seek it? (Acts of the Council of Chalcedon, Session XVI)
How could Rome recognize it as Ecumenical then?
In other words, there must be another formula. Constantinople I was followed by the Council of Ephesus (papal legates arrived late), which confirmed the statements of Constantinople I.
Could it be that the Pope or his legate was invited to Constantinople I but never made it? The Latins seem to think that just inviting the Orthodox is sufficient to make a council "ecumenical." Or, simply declare the Orthodox as schismatics and don't bother calling them!