Synthesis, Spectroscopic Characterization and Thermal Studies of Polymer-Metal Complexes Derived from Modified Poly Styrene-Alt-(Maleic Anhydride) as a Prospects for Biomedical Applications

Abstract

Eight polymer-metal complexes were synthesized from complexation of divalent Mn(II), Ni(II), Co(II), and Cu(II) metal ions with modified polystyrene-alt-(maleic anhydride) (PSMAP and PSMAM) ligands. The structures of these new complexes were characterized using a variety of techniques, including magnetic moment susceptibility, conductance measurements, FT-IR spectroscopy, ultraviolet-visible (UV-VIS), thermogravimetric analysis (TGA), as well as scanning electron microscopy (SEM). All metal-polymer complexes have a non-electrolytic nature based on conductance measurements. The polymer molecule behaves as neutral bidentate NO ligand through O atoms of carbonyl (C=O) and N atoms of amide (O=C-NH). Divalent Mn²⁺, Ni²⁺, Co²⁺ and Cu²⁺ complexes have an octahedral geometry based on their electronic spectra and magnetic values. Based on thermal analysis data, those new complexes are more thermally stable than the ligands. SEM and TEM are manipulated to give the surface structure and the particle size measurements where they give different shapes and sizes of the synthesized complexes.

1. Introduction

The potential sites in the synthetic polymer can coordinate with metal ions to form coordination compound [1]. It is inevitable that the metal atoms bond to the polymer ligands would exhibit characteristic catalytic behavior rather than low molecular weight polymer [2]. In fact, a lot of synthetic metal polymer compounds have been reported to be good catalysts, semiconductor, heat resistance as well as great prospects for biomedical applications [3]. The chelation between metal ions and polymer molecules confers the produced complex great stability in solution and in solid state due to these strong bonds [4,5]. The building block of a polymer; that is an aromatic or aliphatic monomer contains an electronegative donor atom that is nitrogen, sulfur, and oxygen (N, S, and O) reacts as a potential site for coordination to for complex with metal ions [6,7]. The platinum family which involves (Pt, Pd, Ir, Ru, Rh, and Os) can form nano complexes with donor atoms bearing polymer [8]. Furthermore, these types of coordination in polymer chelates facilitate the flow of electrons which explains why they good fluorescent compounds [9]. Different factors facilitate the transfer of electron from donor to acceptor as temperature, pH, NIR, and metal-ion sonication. A series of polyacrylamide and dithiocarbamade metal polymers complexes with divalent Cu, Ni, Zn, Co and Hg metal ion have been prepared, thermal studies have been reported [10]. Moreover, Cross-linked polyacrylamide-Cu(II) complexes with divinylbenzene have been explored for their catalytic activity [10,11]. The thermal studies of polymer complexes derived from chelation between divalent Co, Ni, Cu and Cd metal ions and poly(ethylene glycol) ligand have been investigated [12]. Polymer metal chelates derived from poly(vinyl alcohol) with ferric and copper metal ions have been examined using NMR techniques [13]. The chelate of divalent Cd metal ion with poly (ethylene glycol) have been synthesized and characterized using X-Ray crystallography [14]. Potentiometry was utilized to study the aqueous solution of partially phosphorylated poly (vinyl alcohol) coordinated with some metals of the first-row transition metals [15]. The metal polymer complex structures have been made up of a variety of polymers, including porphyrin [16], pyridinyl [17], pyrene [18], polyethyleneimine [19], salecan [20,21,22], pullulan [23], and chitosan [24]. Depending on their versatile applications, polymer complexes are considered as promising compounds in different fields [25,26,27,28,29]; organic synthesis [30], waste water treatment [31], hydrometallurgy [32], polymer drug grafts [33], medical applications as (MRI) [34,35,36], bioseparation [37,38], drug delivery [39], recovery of trace metal ions [40] and antimicrobial and antiviral agents [41]. In addition, they are also used as models for enzymes [42,43]. They are utilized as chiral, catalytic, conductive, luminescent, magnetic, porous, or nonlinear optical materials [44,45,46,47]. The idea of using macromolecular structures instead of the synthetically rather complicated supramolecular ligands seems to be well founded. It is assumed that a polymer coil forms a steric “cage” for metal(II) ions. In this paper we report on the synthesis and characterization of metal complexation with high molecular-weight polymer ligands containing an efficient 7-amino-4-methylquinolin-2(1H)-one fluorophore and COOH, that quinolinone derivatives are strong donors towards metal ions [48]. Therefore, in our present study we aimed to synthesized eight polymer-metal complexes associated from complexation of divalent Mn(II), Ni(II), Co(II), and Cu(II) metal ions with modified polystyrene-alt-(maleic anhydride) (PSMAP and PSMAM) ligands.

2. Experimental

Materials and Measurements

All reagents used were purchased from Aldrich chemical company. The elemental analyses of carbon, hydrogen, and nitrogen contents were performed using a Perkin Elmer CHN 2400 (USA). The molar conductivities of freshly prepared 10⁻³ mol/cm³ dimethylsulfoxide (DMSO) solutions were measured for the dissolved compounds using Jenway 4010 conductivity meter. A Shimadzu thermo gravimetric analyzer was used to perform thermal analysis (TGA) up to 800 °C with the heating rate 10 °C min⁻¹ under nitrogen atmosphere. The measurement of electronic absorption spectra for complexes was carried out in DMSO solutions on a UNICAM UV-300 spectrophotometer (thickness of cuvette, 1 cm) within the region of 200–600 nm. Scanning electron microscopy (SEM) images were taken in Quanta FEG 250 equipment, the scanning electron microscopic images were captured with magnification power of 500×-to-40,000× at 10 kV. The transmission electron microscopy images (TEM) were performed using JEOL 100s microscopy. Magnetic moments were calculated using the Magnetic Susceptibility Balance, Sherwood Scientific, Cambridge Science Park, Cambridge, England, at Temp 25 °C. The magnetic susceptibility of samples was measured using Gouy’s. Shimandzu FT-IR-8101A spectrophotometer was utilized to record the vibrational spectra of the sample at range 4000–400 cm⁻¹. The conductance measurements for all samples have been recorded with electrometer.

• Preparation of coordination polymers Ligand (PSMAP)

The copolymer Poly [styrene-alt-(maleic anhydride)] (PSMA) (0.05 mol of anhydride groups (10 g)) was dissolved in 70 mL of dry acetone and 7-amino-4-methylquinolin-2(1H)-one (0.0025 mol (0.44g)). Then, the reaction mixture was refluxed under argon with gradual addition of 50 mL from 2-prpoanol and 20 mL of dry dimethylformamide. The reaction mixture was refluxed first for 12 h and then for another 5 h with continuous stirring at room temperature. The white precipitate had been separated out using large amounts of ethyl acetate, filtered off, and dried. The produced precipitate was twice reprecipitated from methanol into diethyl ether, yielding 6.5 g of white polymer ligand (PSMAP) (Scheme 1). IR (film on KBr): υ(O-H) stretch 3447, υ(C-H) stretch 3029, 2926, 2854, υ(C=O) stretch 1718, υ(HN-C=O) 1653, υ(C-C) ring stretch 1496, δ(CH₂) scissoring 1455, δ(C-OH) bend 1400, υ(C-O-C) antisym. stretch, 1200, 1171, 763 and δ(C-H) out-of-plane, ring bend) 702, 548 cm⁻¹ (Figure S1) [48].

• Preparation of coordination polymers Ligand (PSMAM)

The modified polymer (PSMAM) was synthesized typically as mentioned above. However, the reaction mixture was refluxed in 50 mL methanol instead of 2-prpoanol (Scheme 2). IR (film on KBr): υ(O-H) stretch 3447, υ(C-H) stretch 3029, 2926, 2854, υ(C=O) stretch 1718, υ(HN-C=O) 1653, υ(C-C) ring stretch 1496, δ(CH₂) scissoring 1455, δ(C-OH) bend 1400, υ(C-O-C) antisym. stretch, 1200, 1171, and δ(C-H) out-of-plane, ring bend 702, 763, 548 cm⁻¹ (Figure S2) [48].

• Synthesis of [M(PSMAP)₂(Cl)₂](H₂O)_n (M = Mn²⁺, Ni²⁺, Co²⁺ and Cu²⁺) complexes

The metal complexes were prepared by refluxing 1.0 mmol of metal chloride salts of MnCl₂ (0.126 g), CoCl₂.6H₂O (0.238 g), NiCl₂.6H₂O (0.238 g) and CuCl₂.2H₂O (0.170 g) with 20 mL (2.0 mmol; 1.706 g) of PSMAP ligand polymer with (1:2) molar ratio in 60 mL acetone solution. The mixture solutions were refluxed at 60 °C for 2 h. Separating the solid precipitates, washing them multiple times with methanol, and then vacuum-drying them over anhydrous CaCl₂ were the next steps.

• Synthesis of [M(PSMAM)₂(Cl)₂](H₂O)_n (M = Mn²⁺, Ni²⁺, Co²⁺ and Cu²⁺) complexes

The metal complexes were prepared as discussed earlier by replacing PSMAP polymer with (PSMAM) (2.0 mmol; 1.464 g) and acetone solution was replaced by in 2-propanol. The chemical structures of the synthesized metal complexes were confirmed as follows:

• [Mn(PSMAP)₂Cl₂]2H₂O (1)

Solid light brown powder; Yield 78%, m. p ˃ 300 °C; IR (film on KBr): 3447 (O-H stretching); 3029, 2926, 2854 (C-H stretching); 1718 (C=O stretching); 1653 (amide bond); 1496 (C-C ring stretching); 1455 (CH₂ scissoring); 1400 (C-O-H bending); 1200, 1171 (C-O-C antisym. stretch); 763, 702, 548 cm⁻¹ (C-H out-of-plane, ring bending); (Figure S3), UV-Vis absorption at 270 nm(λ_max).

• [Mn(PSMAM)₂Cl₂]2H₂O (2)

Solid light brown powder; yield-64%, m. p ˃ 300 °C; IR (film on KBr): 3447 (O–H stretching); 3029, 2926, 2854 (C–H stretching); 1718 (C=O stretching); 1653 (amide I band); 1496 (C–C ring stretching); 1455 (CH₂ scissoring); 1400 (C–O–H bending); 1200, 1171 (C–O–C antisym. stretching); 763, 702, 548 (C–H out-of-plane, ring bending) cm⁻¹; (Figure S4), UV-Vis absorption at 260nm (λ_max).

• [Ni(PSMAP)₂Cl₂]2H₂O (3)

Green solid, Yield 63%, m. p ˃ 300 °C; IR (film on KBr): 3447 (O-H stretching); 3029, 2926, 2854 (C-H stretching); 1718 (C=O stretching); 1653 (amide bond); 1496 (C-C ring stretching); 1455 (CH₂ scissoring); 1400 (C-O-H bending); 1200, 1171 (C-O-C antisym. stretch); 763, 702, 548 (C-H out-of-plane, ring bending) cm⁻¹; (Figure S5), UV-Vis absorption at 260 nm (λ_max).

• [Ni(PSMAM)₂Cl₂]2H₂O (4)

Green solid; Yield- 77%, m. p ˃ 300 °C; IR (film on KBr): 3447 (O–H stretching); 3029, 2926, 2854 (C-H stretching); 1718 (C=O stretching); 1653 (amide bond); 1496 (C-C ring stretching); 1455 (CH₂ scissoring); 1400 (C-O-H bending); 1200, 1171 (C-O-C antisym. stretching); 763, 702, 548 (C-H out-of-plane, ring bending) cm⁻¹; (Figure S6), UV-Vis absorbance at 230 nm (λ_max).

• [Co(PSMAP)₂Cl₂]H₂O (5)

Solid purple powder; Yield 75%, m. p ˃ 300 °C; IR (film on KBr): 3447 (O-H stretching); 3029, 2926, 2854 (C-H stretching); 1718 (C=O stretching); 1653 (amide bond); 1496 (C-C ring stretching); 1455 (CH₂ scissoring); 1400 (C-O-H bending); 1200, 1171 (C-O-C antisym. stretching); 763, 702, 548 (C-H out-of-plane, ring bending) cm⁻¹; (Figure S7), UV-Vis absorbance at 400nm (λ_max).

• [Co(PSMAM)₂Cl₂]2H₂O (6)

Solid purple powder; Yield 73%, m. p ˃ 300 °C; IR (film on KBr): 3447 (O-H stretching); 3029, 2926, 2854 (C-H stretching); 1718 (C=O stretching); 1653 (amide bond); 1496 (C-C ring stretching); 1455 (CH₂ scissoring); 1400 (C-O-H bending); 1200, 1171 (C-O-C antisym. stretch); 763, 702, 548 (C-H out-of-plane, ring bending) cm⁻¹; (Figure S8), UV-Vis absorbance at 215 nm (λ_max).

• [Cu(PSMAP)₂Cl₂]H₂O (7)

Solid blue powder; Yield 71%, m. p ˃ 300 °C; IR (film on KBr): 3447 (O-H stretching); 3029, 2926, 2854 (C-H stretching); 1718 (C=O stretching); 1653 (amide bond); 1496 (C-C ring stretching); 1455 (CH₂ scissoring); 1400 (C-O-H bending); 1200, 1171 (C-O-C antisym. stretching); 763, 702, 548 (C-H out-of-plane, ring bending) cm⁻¹; (Figure S9), UV-Vis absorbance at 210 nm (λ_max).

• [Cu(PSMAM)₂Cl₂]2H₂O (8)

Solid blue powder; Yield 75%, m. p ˃ 300 °C; IR (film on KBr): 3447 (O-H stretching); 3029, 2926, 2854 (C-H stretching); 1718 (C=O stretching); 1653 (amide bond); 1496 (C-C ring stretching); 1455 (CH₂ scissoring); 1400 (C-O-H bending); 1200, 1171 (C-O-C antisym. stretching); 763, 702, 548 (C-H out-of-plane, ring bending) cm⁻¹; (Figure S10), UV-Vis absorbance at 210 nm (λ_max).

3. Results and Discussion

3.1. Elemental and Conductance Data

The polymer metal complexes were prepared by refluxing different metal salts of Mn(II), Ni(II), Co(II) and Cu(II) with PSMAP and PSMAM ligands. Under ambient circumstances, all the complexes are stable and mostly insoluble in organic solvents except DMF and DMSO as well as they are non-hygroscopic. Elemental analysis as well as other physical data of ligands and its complexes are tabulated in (

Table 1. Physicochemical results of PSMAP, PSMAM ligands and their metal complexes.

No	Compound	Yield%	$\mathsf{\Lambda }\mathbf{m}$ $\mathbf{\left(}{\mathsf{\Omega }}^{-1}\mathbf{\right)}$	Color and m.p (°C)	Elemental Analysis Found (calcd.) %
					C	H	N
	C51H85N2O8 (PSMAP)	79	-	White ˃ 300 °C	71.61 (71.62)	9.83 (9.98)	3.18 (3.21)
	C42H72N2O8 (PSMAM)	64	-	White ˃ 300 °C	66.85 (66.82)	9.70 (9.85)	3.62 (3.75)
(1)	[Mn(PSMAP)2Cl2]·2H2O	78	7	Light brown ˃ 300 °C	65.47 (65.57)	9.12 (9.28)	3.08 (3.00)
(2)	[Mn(PSMAM)2Cl2]·2H2O	64	13	Light brown ˃ 300 °C	61.33 (61.97)	9.14 (9.16)	3.38 (3.44)
(3)	[Ni(PSMAP)2Cl2]·2H2O	63	10	Green ˃ 300 °C	66.53 (66.63)	9.40 (9.54)	3.17 (3.19)
(4)	[Ni(PSMAM)2Cl2]·2H2O	77	8	Green ˃ 300 °C	61.17 (61.83)	9.22 (9.14)	3.57 (3.60)
(5)	[Co(PSMAP)2Cl2]·H2O	75	10	Purple ˃ 300 °C	66.12 (66.00)	9.30 (9.34)	3.03 (3.02)
(6)	[Co(PSMAM)2Cl2]·2H2O	73	12	Purple ˃ 300 °C	61.76 (61.82)	9.12 (9.14)	3.47 (3.43)
(7)	[Cu(PSMAP)2Cl2]·H2O	71	12	Blue ˃ 300 °C	65.70 (65.83)	9.30 (9.32)	3.00 (3.01)
(8)	[Cu(PSMAM)2Cl2]·2H2O	75	8	Blue ˃ 300 °C	61.66 (61.65)	9.15 (9.12)	3.36 (3.42)

). Elemental analysis predicts the formation of 1:2 molar ratio complexes. The conductance measurements of 10⁻³ DMSO solutions of complex samples predict the non-electrolytic nature of complexes reflecting that chloride ions are non-ionizable. The data obtained were in accord with the proposed formulas (Scheme 3 and Scheme 4).

3.2. FT-IR Analysis

The assignments of absorption bands in the vibrational spectra of PSMAP, PSMAM ligands and their metal complexes are given in

Table 2. Vibrational spectral data of the PSMAP, PSMAM ligands and their metal complexes (cm⁻¹).

Polymer	O-H Stretching	C-H Stretching	C=O Stretching	Amide Bond	C-C Ring Stretching	C-O-H Bending	C-O-C Anti Sys Stretching	C-H Out-of Plane, Ring Bending	M-O	M-N
PSMAP	ــــــ	3029, 2926	1718	1653	1496	1455	1400	1200, 1171	ــــــ	ــــــ
PSMAM	ــــــ	3029, 2926	1718	1653	1495	1455	1405	1200, 1171	ــــــ	ــــــ
(1)	3361	3038, 2946	1724	1563	1494	1442	1402	1212, 1166	699	521
(2)	3345	3021, 2944	1703	1562	1497	1447	1405	1210, 1167	705	537
(3)	3371	3028, 2947	1710	1556	1488	1430	1401	1212, 1173	704	532
(4)	3360	3028, 2944	1710	1556	1488	1430	1401	1213, 1173	704	532
(5)	3381	3018, 2943	1700	1553	1494	1436	1408	1217, 1166	693	538
(6)	3366	3035, 2944	1717	1561	1490	1450	1401	1210, 1161	703	515
(7)	3377	3028, 2953	1707	1565	1490	1440	1402	1210, 1172	705	524
(8)	3372	3024, 2935	1707	1563	1493	1415	1404	1213, 1168	705	534

& Figures S1–S10. An insight to the spectra shows broad and weak bands in the region between (3687–3236 cm⁻¹) probable to the stretching vibration of O-H water molecules [49]. The band at 3055–3052 cm⁻¹ may be attributed to C-H aromatic stretching vibrations [50]. The strong band at 1639 cm⁻¹ may be assigned to the amidic (O=C-NH) bonds [51,52] that shifted to lower frequency (1553–1563 cm⁻¹) on coordination to metal ions for complexes (1–8). The presence of a perceptible band for C═O was found at 1665 cm⁻¹ in free ligand, whereas in coordination polymers it was shifted towards the lower frequency relative to the band of the parent ligand which indicates the chelation, then ultimately strengthened the C═N bond as result of polymerization. The absorption bands appear in the spectra at (3018–3038), (1718–1700), (1488–1496), (1161–1200) cm⁻¹ may be characteristic to the stretching vibration of (C-H) stretching, (C=O) stretching of amide, (C-O-C) anti sys stretching, (C-H) out-of-plane, ring bending, respectively. Moreover, there were two additional absorption bands that appeared at 705–693, and 538–515 cm⁻¹ that were attributed to the vibration of Metal-O, and Metal-N, respectively. Besides the bands of uncoordinated water molecule that observed at 3444 –3447, 1533, and 756. Those new bands can strongly prove the formation of complex and the presence of H₂O outside coordination sphere [52].

3.3. Electronic Spectra and Magnetic Investigation of Metal Polymer Complexes

The data listed in

Table 3. Solid reflectance spectral bands (cm⁻¹) and assignments of the PSMAP and PSMAM complexes.

Compounds	Spectral Data	Electronic Transition	${\mathit{\mu }}_{\mathbf{e}\mathbf{f}\mathbf{f}} (\mathbf{B}.\mathbf{M}.)$	Assignments
PSMAP-Mn(II) (1)	16,233 27,397 36,764	6A1g → 4T1g (G) 6A1g → 4T2g (G) 6A1g → 4A1g (G), 4Eg (G)	5.40	Octahedral
PSMAM-Mn(II) (2)	16,666 31,347 38,461	6A1g → 4T1g (G) 6A1g → 4T2g (G) 6A1g → 4A1g (G), 4Eg (G)	5.78	Octahedral
PSMAP-Ni(II) (3)	16,474 21,929 28,985	3A2g (F) → 3T1g (P) 3A2g (F) → 3T1g (F) 3A2g (F) → 3T2g (F)	3.07	Octahedral
PSMAM-Ni(II) (4)	17,241 22,026 31,250	3A2g (F) → 3T1g (P) 3A2g (F) → 3T1g (F) 3A2g (F) → 3T2g (F)	3.18	Octahedral
PSMAP-Co(II) (5)	18,181 14,492	4T1g (F) → 4T1g (P) 4T1g (F) → 4A2g (F)	4.98	Octahedral
PSMAM-Co(II) (6)	17,605 14,749	4T1g (F) → 4T1g (P) 4T1g (F) → 4A2g (F)	4.86	Octahedral
PSMAP-Cu(II) (7)	24.376 17.322 14.556	charge transfer band d-d transitions 2Eg → 2T2g	2.00	Octahedral
PSMAM-Cu(II) (8)	24.376 17.322 14.556	charge transfer band d-d transitions 2Eg → 2T2g	1.58	Octahedral

reveals the electronic spectral data for PSMAP, PSMAM and their metal complexes Figures S11–S18. According to the data tabulated in Table 3, PSMAP-Mn(II) complex shows absorption maxima bands at 272, 365, and 373 nm. PSMAM-Mn(II) complex has four absorption maxima at 260, 287, 319, 349, 376 and 386 nm. PSMAP-Ni(II) shows absorption bands at 362, 283, 345 and 375 nm. PSMAM-Ni(II) complex reveals absorption maxima at 213, 234, 261, 320, 349 and 377 nm. PSMAP-Co(II) complex depicts three at 265, 288 and 415 nm. PSMAM-Co(II) complex displays five absorption maxima at 226, 251, 278, 354 and 378 nm. PSMAP-Cu(II) complex displays absorption bands at 241, 262, 286, 322, 389 and 408 nm. PSMAM-Cu(II) complex displays absorption bands at 211, 253, 293, 353 and 394 nm. The first regional bands at 211–272 nm correspond to a π →π* transitions, whereas the bands existed at 362–415 nm region can be assigned to n→π* transitions type [53,54,55,56]. The solid reflectance spectra of the complexes (1) and (2) demonstrate four weak intensity absorption bands in the ranges of (16.666–16.233), (31.347–27.397), and (38.461–36.764) cm⁻¹ (Table 3). These bands can be attributed to the following transitions, respectively: ⁶A_1g→⁴T_1g, ⁶A₁g→⁴T_2g, ⁶A₁g→⁴A_1g, ⁴E_g(4P) [57]. The absorption bands of the nickel(II) complexes (3) and (4) fall between (17.241–16.474), (22.026–21.929), and (31.250–28.985) cm⁻¹. These bands reveal the complexes have octahedral geometry that attributed to the three spin allowed transitions: ³A_2g(F)→³T_1g(P), ³A_2g(F)→³T_1g(F) and ³A_2g(F)→³T_2g(F), respectively [58]. The electronic spectra of cobalt(II) complex (5) show absorption in the ranges of 18.181 and 14.492 cm⁻¹, which can be attributed to the ⁴T₁g(F)→⁴T₁g(P) and ⁴T₁g(F)→⁴A₂g(F), respectively [59,60]. This suggests an octahedral environment for the divalent cobalt ion. The effective magnetic moment is 4.98 B.M that supports the octahedral argument. The electronic spectra of complex (6) show absorption bands at 17.605 and 14.749 cm⁻¹, which can be attributed to the ⁴T₁g(F)→⁴T₁g(P) and ⁴T₁g(F)→⁴A₂g(F) transitions respectively. These transitions along with the magnetic moment (4.98 B.M) suggest the octahedral environment around divalent cobalt ion [61,62,63]. The spectra of copper(II) complexes (7) and (8) display two bands at 16.318–17.322 cm⁻¹ and 24.038–24.376 cm⁻¹ may be attributed to d-d transitions and a charge transfer band, respectively. Moreover, a broad band at 14.727–14.556 cm⁻¹ due to ²E_g→²T_2g transition and predicts an octahedral symmetry around divalent copper [64].

3.4. Thermal Studies

Figures S19–S23 depict the thermogravimetric analyses (TGA) of the PSMAP, PSMAM ligands, as well as their metal complexes.

Table 4. TGA data of PSMAP, PSMAM ligands and their metal complexes.

No	Compounds	Weight Loss (%)			Lost Species
		TGA Range (°C)	Found	Calc.
	C51H85N2O8	30–100 100–330 330–450	18.14 26.18 55.68	18.26 26.22 55.72	6C2H2 8CO C31H73N2
	C42H72N2O8	30–100 100–320 320–450	17.69 30.58 51.39	17.73 30.56 51.57	5C2H2 8CO C24H62N2
(1)	C102H174Cl2MnN4O18	30–115 115–384 384–450 450–800	1.89 20.51 71.41 6.19	1.92 20.53 71.98 5.57	2H2O 2Cl + 4NO2 + 5C2H2 C92H160O7 MnO↓ + 2C↓
(2)	C84H148Cl2MnN4O18	20–120 120–370 370–450 45–800	2.18 20.39 72.10 5.33	2.21 20.43 72.02 5.34	2H2O 2Cl + 3C2H2 + 4NO2 C78H138O7 MnO↓ + C↓
(3)	C102H174ClN4NiO18	30–120 120–300 300–420 420–800	1.85 23.10 70.16 4.89	1.96 23.26 70.15 4.63	2.5H2O 2Cl + 3NO2 + 8C2H2 C86H154NO9 NiO↓ + 0.5C↓
(4)	C84H148Cl2N4NiO18	30–130 130–300 300–400 400–700	2.15 25.16 67.20 5.49	2.21 25.13 67.28 5.38	2H2O 2Cl + 4NO2 + 6C2H2 C72H132O7 NiO↓ + C↓
(5)	C102H172Cl2CoN4O17	30–130 130–350 350–450 450–780	0.92 26.32 67.90 4.86	0.97 26.28 67.88 4.87	H2O 2Cl + 4NO2 + 9C2H2 C84H154O6 CoO↓ + C↓
(6)	C84H148Cl2CoN4O18 Mw = 1631.93	30–150 150–300 300–430 430–780	2.11 25.19 64.05 8.65	2.21 25.12 66.24 6.43	2H2O 2Cl + 4NO2 + 6C2H2 C72H136O5 CoO↓ + 2.5 C↓
(7)	C102H172Cl2CuN4O17	25–200 200–300 300–450 450–800	0.91 23.35 70.50 5.24	0.97 23.43 70.51 5.09	H2O 2Cl + 4NO2 + 7C2H2 C88H158O6 CuO↓ + C↓
(8)	C84H148Cl2CuN4O18	30–120 120–220 220–450 450–790	2.21 29.82 61.25 6.72	2.20 29.86 61.38 6.56	2H2O 2Cl + 4NO2 + 12C2H2 C66H130O5 CuO↓ + 2C↓

summarizes the mass percentage losses for all compounds. Four thermal decomposition steps of complex (1) are depicted in (Figure S20). The first step occurs at temperature range 30–115 °C with 1.89% observed mass loss (calc.= 1.92%) attributable to the loss of two hydrated H₂O molecules. The second step occurs between 115 and 384 °C with observed mass loss of 20.51 (calculated 20.53%) caused by the degradation of 2Cl + 4NO₂ + 5C₂H₂, while the third step occurs between 384 and 450 °C with an observed weight loss of 71.41% (calculated as 71.98%) that is pertain to the decomposition of the entire compound C₉₂H₁₆₀O₇. The full decomposition of the complex (1) corresponds to the ultimate decomposition stage in the temperature range above 450 °C, yielding MnO + 2C as the end product. Four steps of decomposition are provided by polymer complex (2), as depicted in (Figure S20). The evolution of all hydrated water molecules occurs in initial step at temperature range 20–120 °C. The subsequent step involves the removal of 2Cl + 3C₂H₂ + 4NO₂ at a range of 120–370 °C. Third steps occur at temperature range 370–450 °C corresponding to the removal of the C₇₈H₁₃₈O₇. Above 450 °C, the final stage occurs, leaving MnO + C as a residue. The complex (3) undergoes four thermal degradation steps as shown in (Figure S21). The first step occurs at a range of 30–120 °C. This step involves loss of hydrated 2.5H₂O molecules. Within a temperature range of 120–300 °C, the second stage takes place with removal of 2Cl + 3NO₂ + 8C₂H₂ species. The loss of major entity C₈₆H₁₅₄NO₉ takes place at a range of 300–420 °C. Above the range of 420 °C, NiO + 0.5C exist as a final product. When the complex (4) is heated to 800 °C, the complex (4) undergoes four main decomposition steps as shown in (Figure S21). The TG temperatures of 30–130 °C, 130–300 °C and 300–400 °C caused by loss of 2H₂O, 2Cl + 4NO₂ + 6C₂H₂ and breakdown of the C₇₂H₁₃₂O₇ molecule respectively, it appears likely that the remaining bulk matches NiO + C. The thermal degradation of complex (5) occurs in four decomposition steps as shown in (Figure S22). the mass loss in the initial stage of the decomposition is 0.92%. (calc. = 0.97%) in reference to the disintegration of hydrated H₂O molecules within the 30–130 °C temperature range. The second step with an observed mass loss of 26.32 % (calc. = 26.28%) correspond to the loss of 2Cl + 4NO₂ + 9C₂H₂ molecules. The third degradation step with mass losses (found= 67.90 %, calc.= 67.88%) suggesting the loss of C₈₄H₁₅₄O₆ molecule occur in a range of 350–450 °C. It appears likely that the remaining bulk matches CoO + C. The decomposition reactions of complex (6) occur in four steps from 30 °C to 780°C, as shown in (Figure S22). In this complex, mass loss in the initial stage of the breakdown is 2.11%. (calc. 2.21%) referring to the loss of hydrated 2H₂O molecules at a range of 30–150 °C. The second degradation step proceeds at a temperature between 150 °C and 300 °C with a weight loss ranging from of 25.19%, associated with the loss of the 2Cl + 4NO₂ + 6C₂H₂ molecules. The third step of decomposition occurs at in the temperature range 300–430 °C is accompanied by weight loss (64.05%) corresponding to the loss of C₇₂H₁₃₆O₅. The fourth step of decomposition occurs in the temperature range 430–780 °C and is accompanied by a weight loss (6.36%) corresponding to CoO + 2.5C. Thermal decomposition occurs in the polymer complex (7) in four major steps, as displayed in (Figure S23). Regarding the loss of hydrated H₂O molecules between 25 and 200 °C, the initial step of the decomposition has a mass loss of 0.91% (calc.= 0.97%). Due to the loss of 2Cl, 4NO₂, and 7C₂H₂ molecules, the second degradation step had an observed weight loss of 23.35% (calc. = 23.43%). The loss of C₈₈H₁₅₈O₆ molecules in the 300–450 °C temperature range is correlated with the third thermal breakdown, which results in a weight loss of 70.50% (calculated to be 70.51%). CuO + C is the residual product up to 450 °C. The complex (8) gives four stages of decomposition as shown in (Figure S23). The loss of hydrated 2H₂O molecules within the temperature range of 30–200 °C is represented by the mass loss of 2.21% (calc.= 2.20%) in the initial degradation step. In the initial degradation step, the loss of 2Cl + 4NO₂ + 12C₂H₂ molecules occurs at a range of 30–120 °C. While the next decomposition stage completes the loss of C₆₆H₁₃₀O₅ molecule in a range of 220–450 °C. CuO + 2C are the resultant thermal degradation product.

3.5. SEM and TEM Investigations

The properties of the polymers are significantly influenced by the shape of the molecules as well as how they are arranged within a solid. Figure S24 showed the SEM PSMAP and PSMAM complexes. (Figure S24) showed the SEM of PSMAP-Mn(II) and PSMAM-Mn(II) respectively which showed the shape as irregular stone. The flattened morphology of the tiny grains distributed across the solid matrix in the SEM micrograph of PSMAP-Ni(II) and PSMAM-Ni(II) provides the appearance of a structure resembling a river framework (Figure S24). The complexes of PSMAP-Co(II), PSMAM-Co(II), PSMAP-Cu(II), and PSMAM-Cu(II) shown in (Figure S24), and they appeared to have a plate-like surface with cracks. One of the elements that affects morphology is the presence of metal ions embedded inside the polymer matrix. Images of TEM for polymer complexes (1–8) are shown in (Figure S25) and refer to the formation of spherical black spots with particle sizes starting from 2 μm-500 nanometers.

4. Conclusions

New polymer-metal complexes comprising Mn(II), Ni(II), Co(II), and Cu(II) metal ions with modified poly styrene-alt-(maleic anhydride) (PSMAP and PSMAM) were the target of physical-chemical studies. The molecular structures of the investigated compounds were verified using elemental, Infrared, molar conductance, magnetic, UV-vis, and thermal investigations. The neutral bidentate behavior of the PSMAP and PSMAM ligands is revealed by the vibrational spectra. Coordination occurs through the oxygen of (C=O) and the nitrogen of amide groups as a potential site of coordination with metal ion. All substances having a 1:2 stoichiometry is non-electrolytic, according to molar conductivity studies. All polymer complexes are predicted to have octahedral geometry by magnetic measurements and electronic spectra.