US PATENT SUBCLASS 552 / 218
.~.~ The polycyclo ring system is attached indirectly by nonionic bonding to an additional polycyclo ring system having at least three cyclos (e.g., plural anthracene ring systems attached indirectly to each other by nonionic bonding, etc.)

Current as of: June, 1999
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552 /   HD   ORGANIC COMPOUNDS -- PART OF THE CLASS 532-570 SERIES

*  DD  ORGANIC COMPOUNDS (Class 532, subclass 1) {11}
208  DF  .~ Polycyclo ring system containing anthracene configured ring system having at least one double bond between ring members and having oxygen single bonded or any atom double bonded directly at the 9- and 10-positions (e.g., anthraquinones, etc.) {19}
218.~.~ The polycyclo ring system is attached indirectly by nonionic bonding to an additional polycyclo ring system having at least three cyclos (e.g., plural anthracene ring systems attached indirectly to each other by nonionic bonding, etc.) {1}
219  DF  .~.~.~> Nitrogen, oxygen, sulfur, carbon or halogen bonded directly at beta position of the anthracene configured ring system (i.e. 2-, 3-, 6- or 7 position)

DEFINITION

Classification: 552/218

(under subclass 208) Compounds wherein a polycyclo ring system having at least three cyclos is attached indirectly to the anthracene configured ring system by nonionic bonding.

(1) Note. This subclass contains, for example: [figure]