DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Response to Amendment
The rejections of claims 1, 2, and 21-32 and under 35 USC § 103 over Zhang and Wang are withdrawn by the examiner in view of the amendment filed on 7/22/2026.
Since a new Non-Final Office Action is follows, Applicants’ arguments will not be addressed.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1, 2, 21, and 26 are rejected under 35 U.S.C. 103 as being unpatentable over Wang et al., “Controlling Polyethylene Molecular Weights and Distributions Using Chromium Complexes Supported by SNN-Tridentate Ligands,” Macromolecules 2022, 55, 2433–2443 (“Wang”), in view of Abu-Surrah et al., “New bis(imino)pyridine-iron(II)- and cobalt(II)-based catalysts: synthesis, characterization and activity towards polymerization of ethylene,” J. Organomet. Chem. 648 (2002) 55–61 (“Abu-Surrah”).
Regarding claim 1, Wang teaches SNN-tridentate ligands L1–L6 and chromium complexes Cr1–Cr6 having a quinoline-imine ligand framework containing a sulfur donor substituent attached to the quinoline-containing core (Scheme 1, pp. 2434–2435). Wang teaches sulfur as a thioether donor corresponding to X=S and y=1, and hydrocarbyl sulfur substituents corresponding to R12. Wang further teaches hydrogen, alkyl, aryl, substituted aryl and halogenated aryl substituents within the ligand framework (Scheme 1; “Synthesis of Ligands L1–L6,” pp. 2434–2435; Table 1, pp. 2435–2436).
Wang, however, does not teach the claimed requirement that at least one of the two N-aryl ortho positions corresponding to R7 and R11 is H; its exemplified ligands L1–L6 employ substitution at both corresponding ortho positions.
Abu-Surrah teaches closely related imine-containing ligands in which steric bulk of the aromatic groups is varied and expressly reports that catalysts lacking ortho-alkyl substituents on the aryl groups of the ligand produced only oligomers or polymer traces. Abu-Surrah further teaches that varying aryl-group steric bulk controls molecular weight and that increasing steric bulk increases catalyst productivity. Abu-Surrah specifically prepares 2,6-bis[(1-phenylimino)ethyl]pyridine (3e) from aniline, thereby expressly providing an unsubstituted phenyl group attached to the imine nitrogen, in which both ortho positions are H. The corresponding iron complex 4e was also actually prepared. (See pages 56 and 59 section 3.1.5)
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the imino-N-aryl group of Wang by reducing or eliminating the ortho-alkyl substitution, including employing an unsubstituted phenyl group as taught by Abu-Surrah, thereby providing hydrogen at one or both positions corresponding to R7 and R11, because Abu-Surrah teaches that steric bulk of the imino-aryl groups affects catalytic behavior and that catalysts lacking ortho-alkyl substituents produce oligomers or only traces of polymer. Such modification would have predictably reduced steric bulk adjacent to the imine nitrogen and favored oligomer formation rather than formation of higher-molecular-weight polymer. Abu-Surrah is relied upon for this known N-imino-aryl steric modification and its effect, rather than for replacement of Wang's SNN quinoline framework.
Regarding claim 2, Wang teaches the sulfur-containing quinoline-imine ligand and substituent selections overlapping the recited H, methyl, hydrocarbyl, aryl, substituted aryl and halogenated aryl groups, including methyl, phenyl, substituted phenyl and trifluoromethyl-substituted phenyl groups (Scheme 1, pp. 2434–2435; Table 1, pp. 2435–2436). Wang does not teach the required H at R7 or R11. Abu-Surrah teaches an unsubstituted imino-N-phenyl group, necessarily having H at both ortho positions, as discussed above. It would have been obvious to make the modification for the reasons stated regarding claim 1.
Regarding claim 21, Wang does not teach R7 or R11 being H. Abu-Surrah expressly prepares the imino-N-phenyl ligand 3e from unsubstituted aniline, thereby providing H at both ortho positions, and teaches that absence of ortho-alkyl substitution is associated with oligomer formation or only traces of polymer. It would have been obvious to provide R7 or R11 as H for the reasons stated regarding claim 1.
Regarding claim 26, Wang expressly teaches the claimed X=S and y=1 sulfur embodiment (Scheme 1, pp. 2434–2435), but does not teach R7 or R11 being H. Abu-Surrah teaches the missing hydrogen substitution and the reason for reducing ortho steric bulk as discussed above. Accordingly, it would have been obvious to modify Wang to provide the recited sulfur-containing ligand having R7 or R11 as H.
Claims 1 and 22-25 and 27-33 are rejected under 35 U.S.C. 103 as being unpatentable over Zhang et al., “Phosphine-Iminoquinoline Iron Complexes for Ethylene Polymerization and Copolymerization,” Organometallics 2017, 36, 3758–3764 (“Zhang”), in view of Abu-Surrah.
Regarding claim 1, Zhang teaches phosphine-iminoquinoline PNN ligands having the claimed quinoline-imine framework. Zhang prepares iminoquinolines by condensation of 2-acetyl-8-bromoquinoline with arylamines and couples the resulting iminoquinolines with secondary diaryl- or dialkylphosphines R′2PH to produce the PNN ligands, thereby teaching X=P, y=2, with R12 being hydrocarbyl groups (Scheme 1, pp. 3758–3759). Zhang expressly exemplifies iPr2P, tBu2P, Ph2P, p-MeOC6H4-substituted P and p-CF3C6H4-substituted P groups.
Zhang, however, prepares its iminoquinolines using arylamines having iPr or Me substituents at both 2,6-positions and therefore does not teach the requirement that at least one of R7/R11 is H.
Abu-Surrah teaches imine-containing ethylene catalysts having an unsubstituted phenyl group attached to the imine nitrogen, specifically ligand 3e prepared from aniline, thereby providing H at both ortho positions. Abu-Surrah further teaches that catalysts lacking ortho-alkyl substituents produce oligomers or polymer traces. (See pages 56 and 59 section 3.1.5)
The teachings are consistent with Zhang's own recognition that the 2,6-substituents of the N-aryl group are result-effective steric variables: Zhang states that modification of the N-aryl and phosphino substituents tunes the steric/electronic properties, and experimentally shows that reducing the N-aryl ortho substituents from iPr to Me decreases polymer molecular weight. Zhang also attributes its generally lower-MW products to reduced steric blocking and greater chain-transfer rates.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to further reduce the steric bulk at the imino-N-aryl group of Zhang by reducing or eliminating the ortho-alkyl substituents, including employing an unsubstituted phenyl group as taught by Abu-Surrah, thereby providing hydrogen at one or both positions corresponding to R7 and R11, because Zhang teaches that reduced N-aryl steric bulk increases chain transfer and decreases polymer molecular weight, while Abu-Surrah expressly teaches that catalysts lacking ortho-alkyl substituents produce oligomers or only traces of polymer. The modification therefore would have predictably favored oligomer/lower-molecular-weight product formation.
Regarding claim 22, Zhang expressly teaches X=P and y=2 through its secondary diaryl- and dialkylphosphine-derived PNN ligands. Abu-Surrah supplies the inherited R7-or-R11=H limitation through its unsubstituted N-phenyl ligand. The combination renders claim 22 obvious for the reasons stated regarding claim 1.
Regarding claim 23, Zhang's PNN ligands have the quinoline framework derived from 2-acetyl-8-bromoquinoline, with the unsubstituted quinoline positions being H and the imine-carbon substituent being methyl, thereby satisfying the recited selection of R1-R6 as H or methyl (Scheme 1, pp. 3758–3759). The inherited ortho-H limitation is supplied by Abu-Surrah as discussed above.
Regarding claim 24, Zhang teaches R12 selections falling within the claimed group, including alkyl and phenyl, through the iPr2P, tBu2P and Ph2P ligands, and additionally teaches substituted phenyl phosphines (Scheme 1; complexes 3a–3j). Thus Zhang expressly teaches species falling within the recited R12 alternatives.
Regarding claim 25, Zhang's ligand is derived from 2-acetyl-8-bromoquinoline, thereby providing the methyl substituent at the imine carbon and H at the otherwise unsubstituted quinoline positions, corresponding to the claimed R1–R5=H and R6=methyl arrangement (Scheme 1, pp. 3758–3759). Abu-Surrah supplies the inherited N-aryl ortho-H limitation.
Regarding claim 27, Zhang does not teach both R7 and R11 being H, because its N-aryl rings contain either iPr or Me at both 2,6-positions. Abu-Surrah expressly prepares 2,6-bis[(1-phenylimino)ethyl]pyridine (3e) from aniline, providing an unsubstituted imino-N-phenyl group and therefore H at both ortho positions. It would have been obvious to employ that unsubstituted N-phenyl arrangement in Zhang for the steric/chain-transfer and oligomerization reasons stated above.
Regarding claim 28, Zhang expressly teaches X=P and y=2, as discussed regarding claim 22. Abu-Surrah supplies the inherited R7=R11=H limitation.
Regarding claim 29, Zhang teaches the 2-acetyl-derived phosphine-iminoquinoline framework having the recited H/methyl substitution of R1–R6 (Scheme 1, pp. 3758–3759). Abu-Surrah supplies both ortho hydrogens.
Regarding claim 30, Zhang teaches R12 species within the claimed selection, particularly alkyl and phenyl groups through its iPr2P, tBu2P and Ph2P embodiments.
Regarding claim 31, Zhang's 2-acetyl-iminoquinoline framework provides the recited arrangement of R1–R5=H and R6=methyl, as discussed regarding claim 25 (Scheme 1, pp. 3758–3759).
Regarding claim 32, the modified Zhang ligand has R7=R11=H as taught by Abu-Surrah, while the remaining N-aryl position(s) are H in Abu-Surrah's unsubstituted phenyl embodiment; H is one of the alternatives recited for R8–R10. Abu-Surrah's actual synthesis from aniline establishes this unsubstituted phenyl structure. Accordingly, claim 32 would have been obvious for the same reasons stated regarding claims 27–31.
Regarding claim 33, Zhang, however, does not teach at least one of R7 and R11 being H, because its N-aryl groups contain Me or iPr at both ortho positions. Abu-Surrah teaches an imino-N-phenyl ligand prepared from unsubstituted aniline, thereby providing hydrogen at both positions corresponding to R7 and R11. Abu-Surrah further teaches that catalysts lacking ortho-alkyl substituents on the imino-aryl groups produce oligomers or only traces of polymer.
Zhang itself teaches that reducing steric bulk at the N-aryl group from iPr to Me decreases polymer molecular weight and attributes reduced steric protection to increased chain-transfer rates and formation of lower-molecular-weight products.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the N-aryl group of Zhang by further reducing or eliminating the ortho-alkyl substitution, including employing an unsubstituted phenyl group as taught by Abu-Surrah, thereby providing at least one of R7 and R11 as H, because Zhang teaches that reduced N-aryl steric bulk increases chain transfer and decreases polymer molecular weight, while Abu-Surrah teaches that elimination of ortho-alkyl substitution results in oligomers or only traces of polymer. The resulting modified Zhang ligand would have X=P, y=2, R1–R5=H, R6=methyl, R9=H, at least one of R7/R11=H, and the claimed hydrocarbyl R12 groups, thereby meeting claim 33.
Conclusion
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/TAM M NGUYEN/Primary Examiner, Art Unit 1771
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