Companies do business with vendors to do business. Urging them to give to certain charities should not be encouraged but discouraged. Every individual has their opinions of non-profit organizations so do not bring these opinions into the workplace. If you wish, brag about your company giving $50,000 to the Red Cross, or $10,000 to the local orphanage, or $ $50,000 for cancer research. Put it on your website and let everyone know you contribute. Do not force this on your vendors.